patterns of terrorism in the united states, year 3 project 2.4 gtd-us final_0.pdfpatterns of...

National Consortium for the Study of Terrorism and Responses to Terrorism A Department of Homeland Security Science and Technology Center of Excellence

Based at the University of Maryland

8400 Baltimore Ave, Suite 250 • College Park, MD 20740 • 301.405.6600 www.start.umd.edu

PatternsofTerrorismintheUnitedStates,1970‐2014ReporttotheOfficeofUniversityPrograms,ScienceandTechnologyDirectorate,U.S.DepartmentofHomelandSecurityMay2016


Patterns of Terrorism in the United States, 1970-2014 1

AboutThisReport

TheauthorofthisreportisErinMillerattheUniversityofMaryland.QuestionsaboutthisreportshouldbedirectedtoErinMillerateemiller@umd.edu.TheinitialcollectionofdatafortheGlobalTerrorismDatabase(GTD)datawascarriedoutbythePinkertonGlobalIntelligenceServices(PGIS)between1970and1997andwasdonatedtotheUniversityofMarylandin2001.DigitizingandvalidatingtheoriginalGTDdatafrom1970to1997wasfundedbyagrantfromtheNationalInstituteofJusticein2004(PIsGaryLaFreeandLauraDugan;grantnumber:NIJ2002‐DT‐CX‐0001)andin2005aspartoftheSTARTCenterofExcellencebytheDepartmentofHomelandSecurityScienceandTechnologyDirectorate(DHSS&T),OfficeofUniversityPrograms(PIGaryLaFree;grantnumbersN00140510629and2008‐ST‐061‐ST0004).DatacollectionforincidentsthatoccurredbetweenJanuary1998andMarch2008andupdatestotheearlierdatatomakeitconsistentwithnewGTDcodingcriteriawerefundedbytheDHSS&THumanFactors/BehavioralSciencesDivision(HFD)(PIsGaryLaFreeandGaryAckerman;contractnumberHSHQDC‐05‐X‐00482)andconductedbydatabasestaffattheNationalConsortiumfortheStudyofTerrorismandResponsestoTerrorism(START)andtheCenterforTerrorismandIntelligenceStudies(CETIS).ForGTDdatacollectionfromApril2008toOctober2011,STARTpartneredwiththeInstitutefortheStudyofViolentGroups(ISVG),headquarteredatNewHavenUniversity.TheseeffortswerefundedbyagrantfromDHSS&TOfficeofUniversityPrograms,(PIGaryLaFree;grantnumber2008‐ST‐061‐ST0004).BeginningwitheventsthatoccurredinNovember2011,theSTARTConsortiumheadquarteredattheUniversityofMarylandbegancollectingalldatafortheGTDindependently.Sincethen,allGTDcollectionhasbeenjointlyfundedbyDHSS&TOfficeofUniversityPrograms(PIGaryLaFree;grantnumber2012‐ST‐061‐CS0001)andbytheU.S.StateDepartment(PIsGaryLaFreeandErinMiller;contractnumberSAQMMA12M1292).TheGTDnowincludesinformationon141,966terroristattacksfromaroundtheworldfrom1970through2014andcanbeaccesseddirectlyfromtheSTARTwebsite.Inadditiontoongoingdatacollection,effortstoreviewandupdateinformationonterroristattacksintheUnitedStateshavebeensupportedthroughfundingfromtheDHSS&TResilientSystemsDivision(PIGaryLaFree,grantnumber#2009ST108LR0003).Beginningin2009,effortstosupplementGTDdatafortheUnitedStateshaveincludedsystematicallyreviewingnumerouschronologiesofterrorismandpoliticalviolencetoidentifycasesthatqualifyforinclusionintheGTD,aswellasupdatingexistingGTDcaseswithnewinformation.ThisreportfocusesontheU.S.segmentoftheGlobalTerrorismDatabase.Anearlierversionofthisreportwaspublishedin2014.

AboutSTART

TheNationalConsortiumfortheStudyofTerrorismandResponsestoTerrorism(START)issupportedinpartbytheScienceandTechnologyDirectorateoftheU.S.DepartmentofHomelandSecuritythroughaCenterofExcellenceprogrambasedattheUniversityofMaryland.STARTusesstate‐of‐the‐arttheories,methodsanddatafromthesocialandbehavioralsciencestoimproveunderstandingoftheorigins,



dynamicsandsocialandpsychologicalimpactsofterrorism.Formoreinformation,[email protected].

Citations

Tocitethisreport,pleaseusethisformat:

Miller,Erin.PatternsofTerrorismintheUnitedStates,1970‐2014.CollegePark,MD:START,2016.

Apreviousversionofthisreportwaspublishedin2014:

Miller,Erin.PatternsofTerrorismintheUnitedStates,1970‐2013:FinalReporttoResilientSystemsDivision,DHSScienceandTechnologyDirectorate.CollegePark,MD:START,2014.



ContentsExecutiveSummary..............................................................................................................................................................................4

Introduction.............................................................................................................................................................................................6

DataCollectionMethodology............................................................................................................................................................6

ProcessingSourceDocuments....................................................................................................................................................6

DefiningTerrorism...........................................................................................................................................................................7

VariablesandCoding.......................................................................................................................................................................8

MethodologicalConsistency.........................................................................................................................................................8

TerrorismintheUnitedStates.........................................................................................................................................................9

AttackPatternsandLethality......................................................................................................................................................9

PerpetratorsofTerrorismintheUnitedStates................................................................................................................12

SpatialPatternsofTerrorismintheUnitedStates..........................................................................................................18

WeaponsUsedinTerroristAttacksintheUnitedStates..............................................................................................20

TargetsofTerroristAttacksintheUnitedStates.............................................................................................................24

Conclusions............................................................................................................................................................................................30

Endnotes.................................................................................................................................................................................................31



ExecutiveSummaryAlthoughterroristattacksoccurworldwide,aggregatedglobaltrendsmaskimportantvariationattheregional,national,andlocallevel.Recognitionofthesenuancesiscriticalforunderstandingthebroadercausesandconsequencesofterrorism.Inparticular,patternsofterrorismintheUnitedStatesareunique,characterizedbyespeciallydistinctivetrendsinthenumberofattacksovertime,thelethalityofattacks,andthediversityofperpetrators,weapons,andtargets.InthisreportweexaminepatternsofterrorismintheUnitedStatesfrom1970to2014basedonanalysisoftheGlobalTerrorismDatabase(GTD).1AttackPatternsandLethality

Morethan2,600terroristattackstookplaceintheUnitedStatesbetween1970and2014;56percentoftheseattackstookplaceinthe1970s.

Morethan3,500peoplewerekilledinterroristattacksintheUnitedStates;howeverthevastmajorityofdeaths(85%)tookplaceonasingleday—September11,2001.Anadditional5percentofalldeathswerearesultofthe1995attackontheAlfredP.MurrahFederalBuildinginOklahomaCity.

NinetypercentofterroristattacksintheUnitedStatesbetween1970and2014werenotlethal.

ThepercentageofallattacksintheUnitedStatesthatwerelethalrangedfromaminimumofzero(in2000,2003,2004,2005,2007,and2011)toamaximumof58percentin2014.

Theamountofpropertydamagecausedbynon‐lethalattacksintheUnitedStatesbetween1970and2014totaledmorethan$224million.Thedamageamountsassociatedwitheachattackrangedfrom$50to$45million.

Between1970and2014,18percentoftheattacksthattookplaceintheUnitedStateswereunsuccessful,meaningtheperpetratorswereeitherontheirwaytocarryouttheattackorhadattemptedtocarryouttheattack,buteitherfailedorwerethwartedbyauthorities.Thiswastwicetheprevalenceofunsuccessfulattacksworldwide(9%).

PerpetratorsofTerrorismintheUnitedStates

Informationabouttheperpetratorsofattackswasavailablefor82percentofallattacksintheUnitedStatesbetween1970and2014.Ofthese,60percentwereattributedtomorethan160namedorganizations;32percentwereattributedtoperpetratorsdescribedusingagenericidentity(e.g.,“studentradicals”);and8percentwereattributedtounaffiliatedindividuals.For18percentofallattacksintheUnitedStates,noinformationontheperpetratorwasavailable.

Whenexaminingpatternsofperpetratoractivitybydecade,wecanobserveshiftsovertime.o Terroristattacksinthe1970swerepredominantlycarriedoutbyleft‐wingextremists

andPuertoRicannationalists.o Inthe1980s,attacksbyleft‐wingextremistsdecreased,andattacksbyperpetrators

motivatedbyanti‐abortionextremismbecamemuchmorecommon. o Inthe1990s,terroristviolencetargetingabortionproviderscontinued,andviolence

motivatedbyenvironmentalextremismbecamemoreprevalentwhileattacksbyleft‐wingextremistsandPuertoRicannationalistsbecameextremelyrare.

1TheGTDdefinesterrorismas“thethreatenedoractualuseofillegalforceandviolencebyanon‐stateactortoachieveapolitical,economic,religious,orsocialgoalthroughfear,coercion,orintimidation.”



o From2000to2014,theperpetratorsofattackswereverydiversewithrespecttotheirideologicalmotivations,and29percentofattackswereconductedbyunaffiliatedindividuals.

SpatialPatternsofTerrorism intheUnited States

Terroristattacksoccurredinall50states,theDistrictofColumbia,andPuertoRico;howevertheyhavebeenespeciallyprevalentincertainlocations.HalfofalloftheattacksintheUnitedStatesbetween1970and2014tookplaceinCalifornia(22%),NewYork(19%),andPuertoRico(9%).

Thispatternshiftedovertime,however.WhileattacksconsistentlyoccurredinCaliforniaandNewYork,thelocationoftheremainingattackshasbecomeincreasinglydiffuseandsomewhatunpredictable.

WeaponsUsedinTerroristAttacksintheUnited States

TheweaponsusedinterroristattacksintheUnitedStatesdiffereddistinctlyfromworldwidetrends.Perhapsmostnotably,theuseofincendiarieswas3.75timesasprevalentintheUnitedStatescomparedtoglobalpatterns.Incontrast,theuseoffirearmswas2.63timesasprevalentgloballyasitwasintheUnitedStates.

Betweenthe1970sand2000s,thepercentageofweaponsthatwereincendiariesmorethandoubled,whilethepercentageofweaponsthatwereexplosivesdecreasedbytwo‐thirdsandthepercentageofweaponsthatwerefirearmsincreasedmorethan10percent.

TargetsofTerroristAttacksintheUnitedStates

TerroristattacksintheUnitedStatestargetedawidevarietyofentities,butthemostcommontargetsbetween1970and2014werebusinesses(28%),followedbynon‐diplomaticgovernmenttargets(13%)andprivatecitizensandproperty(12%).

Despiteadecreaseinthenumberofterroristattacks,thetargetsofthe289attacksbetween2000and2014remaineddiverse—18differenttypesoftargetswereattacked.

ThethreatofterrorismintheUnitedStatesisfarfromuniform.Inthe1970s,1980s,and1990s,certainpatternsemergedregardingtheperpetratorsofterrorism,themovementstheyrepresented,andthetacticstheyadopted.Inthefirst15yearsofthe21stcentury,perpetratorsandtargetsintheUnitedStateswereespeciallyvariedandlesspredictable.Attackswerefrequentlycarriedoutanonymously,andperpetratorswereofteneitherunidentifiedorunaffiliatedwithaformallyorganizedgroup.TerroristattacksintheUnitedStatesbetween2000and2014wererelativelyinfrequentcomparedtoearlierdecades,buttheywereespeciallyvariedwithrespecttolethality,perpetratormotivation(basedoneithertheidentificationoftheperpetratororthesymbolismofthetarget),location,typesofweaponsused,andtypesoftargetsattacked.



IntroductionAlthoughterroristattacksoccurworldwide,aggregatedglobaltrendsmaskimportantvariationattheregional,national,andlocallevel.In‐depthanalysisrevealsimportantnuancesinpatternsofterrorismforaparticularplaceortimeperiod,whichislargelyshapedbythecharacteristicsofperpetratorsandperpetratorgroupsresponsiblefortheattacks.Recognitionofthesenuancesiscriticalforunderstandingthebroadercausesandconsequencesofterrorism.Inparticular,patternsofterrorismintheUnitedStatesareunique,characterizedbyespeciallydistinctivetrendsinthenumberofattacksovertime,thelethalityofattacks,andthediversityofperpetrators,weapons,andtargets.InthisreportweexaminepatternsofterrorismintheUnitedStatesfrom1970to2014.WebeginbydescribingthedatacollectionmethodologyfortheGlobalTerrorismDatabase(GTD)andconcludewithgeneralobservationsabouttheimplicationsofthisanalysisforadditionalresearchandpolicy.

DataCollectionMethodology2TheGlobalTerrorismDatabaseistheresultofmultipledatacollectioneffortscarriedoutsince1970thathavereliedonpubliclyavailable,unclassifiedsourcematerials,mainlymediaarticlesandelectronicnewsarchives.ThedatathatoriginallycomprisedthecoreoftheGTDfrom1970to1997werecollectedbyPinkertonGlobalIntelligenceServices(PGIS)onhandwrittenindexcards.Beginningin2001,ateamofresearchersattheUniversityofMarylandobtainedtheseoriginalrecordsanddigitizedthem.By2006themaintenanceofthisdatasethadbecomeakeycomponentoftheresearchportfoliodevelopedbytheNationalConsortiumfortheStudyofTerrorismandResponsestoTerrorism(START),andtheGTDteambeganpartneringwithotherorganizationstocarryoutongoingdatacollectionforeventsthattookplaceafter1997.Throughoutthisperiod,STARTresearchersconductedsupplementaldatacollectionprojectstosystematicallycomparetheGTDtoothersourcesofdatatoimproveitscompletenessandworkedtoupdatehistoricaleventdetailswhenpossible.In2012,theGTDteamatSTARTmovedtheprimarydatacollectionefforttoSTARTheadquartersattheUniversityofMaryland.Sincethen,STARThasassumedsoleresponsibilityforallaspectsofthecollectionandmaintenanceoftheGTD.Toaccomplishthis,wedevelopedaninnovativedatacollectionmethodologyfortheGTDthatisbasedonmorethan10yearsofexperienceandlessonslearnedwithrespecttothecomplexitiesandchallengesofsystematicallycollectingvaliddataonterroristattacksworldwide.

ProcessingSourceDocumentsWithintheevolvingframeworkofnewsmediaandtechnology,START’sobjectiveistoenhancetheefficiency,accuracy,andcompletenessofGTDcollection.Weaccomplishthisbycombiningthestrengthsofbothautomatedandmanualtechniques.Thedatacollectionprocessdrawsonmorethanonemillionmediaarticlesonanytopicpublisheddailyworldwide.Theprocessofidentifyingtherelativelysmallsubsetofthesearticlesthatdescribeterroristattacksbeginswithapplyingcustomizedkeywordfilterstothe“firehose”ofmediaarticlesavailablethroughasubscriptiontotheMetabaseApplicationProgrammingInterface(API)providedbyMoreoverTechnologies,Inc.WesupplementtheEnglish‐languagecontentfromMetabasewitharticlesdownloadedfromtheOpenSourceCenter(www.opensource.gov),whichincludesEnglish‐languagetranslationsofsourcesfrommorethan160

2AdditionalinformationaboutthedatacollectionmethodologycanbefoundontheGTDwebsiteandintheGTDcodebook.



countriesinmorethan80languages.Theinitialfiltersisolateapoolofpotentiallyrelevantarticles,approximately200,000permonth.Wereducethissubsetusingmoresophisticatednaturallanguageprocessingandmachinelearningtechniquestoremoveduplicatesandscorethelikelyrelevanceofthearticles.TheGTDteammanuallyreviewsthissecondsubsetofarticles,approximately20,000eachmonth,toidentifytheuniqueeventsthatsatisfytheGTDinclusioncriteria.Finally,thecodingteamreadsthearticlesthatarelinkedtospecificeventsandrecordsthedetailsofeacheventaccordingtothespecificationsoftheGTDCodebook.

DefiningTerrorismTheGTDdefinesterrorismas“thethreatenedoractualuseofillegalforceandviolencebyanon‐stateactortoachieveapolitical,economic,religious,orsocialgoalthroughfear,coercion,orintimidation.”Tooperationalizethisdefinition,GTDresearchersincludeinthedatabasethoseincidentsthatsatisfyeachofthefollowingmandatoryinclusioncriteria:

Theincidentmustbeintentional,i.e.,theresultofaconsciouscalculationonthepartofaperpetrator.

Theincidentmustentailsomelevelofviolenceorthreatofviolence,includingpropertyviolenceaswellasviolenceagainstpeople.

Theperpetratorsoftheincidentsmustbesub‐nationalactors.Thedatabasedoesnotincludeactsofstateterrorism.

Inaddition,incidentsrecordedintheGTDmustmeetatleasttwoofthefollowinginclusioncriteria:

1. Theactmustbeaimedatattainingapolitical,economic,religious,orsocialgoal.2. Theremustbeevidenceofanintentiontocoerce,intimidate,orconveysomeothermessagetoa

largeraudience(oraudiences)thantheimmediatevictims.3. TheactionmustbeoutsidethepreceptsofInternationalHumanitarianLawinsofarasittargets

non‐combatants.

Giventhatitcanbedifficulttounambiguouslydetermineifaneventsatisfiestheseinclusioncriteria,theGTDrecordsalsoincludeavariableindicatingwhetherornotthereisspecificdoubtthattheinclusioncriteriaaresatisfied.Suchdoubtistypicallyaresultofincompleteorconflictingreportsaboutthecircumstancesoftheattack.Theseattacksareincludedintheanalysispresentedinthisreport.Inaddition,inclusionintheGTDrequiresthatsomekineticactionhasbeentakenonthepartoftheperpetratorstocarryouttheattack.Weinformallyrefertothisasthe“outthedoor”rule,inthattheperpetratorsmustbeontheirwaytocarryouttheattacktobeincludedintheGTD.Oncetheperpetratorsare“outthedoor,”iftheattackfailsorisotherwisethwartedweincludeitinthedatabaseandmarkitasunsuccessful.TheGTDdoesnotincludeplots,conspiracies,orhoaxesthatwerenotactuallyattempted.TheGTDdoesnotincludeviolencethatoccursspontaneously,suchasriotingorviolenceprecipitatedbytheactionsofauthorities(e.g.,policeraid,trafficstop,orarrest).TheGTDalsodoesnotincludenon‐violentactivitysuchaspeacefulprotests,vandalism,orcivildisobedience.



VariablesandCodingTheGTDcodingstrategyreliesonsixcodingteamsthateachspecializesonaparticulardomainoftheGTDCodebook.Thedomainsincludelocation,perpetrators,targets,weaponsandtactics,casualtiesandconsequences,andgeneralinformation.Eachteamiscomprisedofthreetosixundergraduateorgraduatestudentinternsledbyaresearchassistant,andisresponsibleforcodingthedomain‐specificvariablesforeacheventintheGTD.Thedomainteamleadersareresponsibleforthetrainingandsupervisionofteammembersandensuringthequalityofthecodeddata.Thisapproachguaranteesthateachpieceofinformationiscodedandreviewedbysomeonewhoisfamiliarwiththeparticularcodingguidelinesforthedomain,aswellastherelevantcontext.Forexample,theperpetratordomainteamwillhavegreaterfamiliaritywithactiveperpetratororganizations,theirnamingconventions,aliases,spellingvariations,factions,andsplinterorganizations,makingthemwell‐suitedtosystematicallyrecordinformationontheorganizationsattributedresponsibilityforanattack.

MethodologicalConsistencyAlthoughthedatacollectionprocessrecentlydevelopedattheUniversityofMarylandhasimprovedtheinternalconsistencyandcomprehensivenessoftheGTD,aswithanyshiftindatacollectionmethodologyitiscriticaltorecognizetheimplicationsforanalysis.Thefirstyearofdatacollectedunderthenewprocess,2012,representsanearly70percentincreaseinthetotalnumberofworldwideterroristattacksover2011.Themagnitudeofthischangeisfarfromuniformacrosscountriesandtheincreaselikelyreflectsrecentpatternsofterrorismincertainlocations.However,itisalsopartlyaresultoftheimprovedefficiencyofthedatacollectionprocess.Theongoingrapidgrowthoftheinternet,andnewsarchivesandaggregatorsinparticular,makesaproductlikeMetabaseavailabletoresearchers,implicitlyimprovingaccesstoagreatervarietyofnationalandlocalsources.TheuseofautomatedapproachestodocumentclassificationallowstheGTDteamtofocusmoretimereviewingonlythosesourcearticlesthatareclassifiedas“relevant”bymachinelearningalgorithms.Asaresult,wehavetheresourcestoleverageamuchbroaderanddeeperpoolofmediasourcesfromaroundtheworld.Despiteconsistencyinourdefinitionofterrorismandinclusioncriteria,thisexponentialgrowthinavailablesourcematerialshasallowedustocollectmorecomprehensivedataonterrorismthananypreviouseffort.TheGTDresearchteamwillcontinuetoevaluatetheimpactofsourceavailabilityontrendsinthedatabasetobetteradviseusersonimportantimplicationsforanalysis.WewillalsocontinuetoworktosupplementtheGTD“legacy”dataonterroristattackssince1970tofurtherimproveitscompleteness.Ingeneral,comparisonsofaggregatestatisticsovertimeandbetweenlocations—andtheirimplicationsforthestateofinternationalsecurityandglobalcounterterrorismefforts—shouldbeinterpretedwithcautionduetoconsiderablevariationintheavailabilityofsourcematerials.However,becausetheavailabilityofsourceinformationpertainingtotheUnitedStateshasalwaysbeenrelativelyrobust,andtheGTDteamhasconductedextensivesupplementaldatacollectioneffortsforincidentsoccurringintheUnitedStates,weexpectthatthemethodologicalartifactsdescribedherehaveaminimalimpactonanalysisdescribedinthisreport.



TerrorismintheUnitedStates

AttackPatternsandLethalityBetween1970and2014,2,683terroristattackstookplaceintheUnitedStates.PerhapsthemostremarkableobservationabouttrendsinterrorismintheUnitedStatesovertimeisthefactthatthemajorityoftheseattacks(55%)occurredinthe1970s.3ThepeakfrequencyofterroristattacksintheUnitedStatesrecordedintheGTDwasin1970,whenmorethan460attackswerecarriedout.Intheearly1970sthenumberofattackseachyeardeclineddramatically,firstdroppingbelow100in1972.Afteraslightincreaseinthemid‐1970s,terrorismcontinuedtodecreasesteadilyinthe1980sand1990s,andtheaveragenumberofattackseachyearthroughoutthesetwodecadeswaslessthan50.Since2000,thefrequencyofterroristattacksintheUnitedStateshascontinuedtodecrease,averagingfewerthan20attacksperyearbetween2000and2014.Duringthistimeperiod,theUnitedStateswasranked32ndamongcountriesintermsoftotalnumberofterroristattacks.

Figure1:TotalterroristattacksandlethalterroristattacksintheUnitedStatesbyyear,1970‐2014

Thenumberofterroristattacksacountryexperiencesrepresentsonlyonedimensionoftheoverallthreat.Itisalsoimportanttoexaminethelethalityofattacks.Morethan3,500people(includingperpetrators)werekilledbyterroristattacksintheUnitedStatesbetween1970and2014.Whatisremarkableisthat85percentofalldeathsfromterroristattacksintheUnitedStatesduringthistimeperiodresultedfromthefourcoordinatedattacksonSeptember11,2001.Anadditional5percentoffatalitiesweretheresultofthe1995attackontheAlfredP.MurrahFederalBuildinginOklahomaCity.

3Datafrom1993aretypicallynotincludedintheGTDbecausetheoriginalrecordswerelostinanofficemovebeforethedataweretransferredtoSTART.However,thesupplementaldataforterroristattackstheUnitedStatesin1993aresufficientlyrobustandareincludedinthestatisticsinthisreport.Collectionandrevisionofthedataareongoing,andtheexactnumbersofattackspresentedinthisreportmaychangeslightlyasnewdatabecomeavailable.

0

50

100

150

200

250

300

350

400

450

500

Num

ber o

f Att

acks

Year

Total Attacks

Lethal Attacks

Source: Global Terrorism Database



Incontrast,90percentofterroristattacksintheUnitedStatesbetween1970and2014werenotlethal.TheprevalenceoflethalterroristattacksintheUnitedStatesvariesconsiderablyovertime,butdoesnotappeartofollowaparticulartrend.Thepercentageofallattacksthatwerelethalrangesfromaminimumofzero(in2000,2003,2004,2005,2007,and2011)toamaximumof58percentin2014.Note,however,thatthevariationinpercentagesisespeciallyextremesince2000duetotheparticularlylowfrequencyofattacks.Duringthe2000‐2014timeperiod,theUnitedStatesranked11thamongcountriesintermsoftotalnumberoffatalitiesduetoterroristattacks.Iftheunprecedentedcasualtiesthatresultedfromthe9/11attackswerenotincluded,theUnitedStateswouldhaveranked54th.

Figure2:PercentofterroristattacksintheUnitedStatesthatwerelethalbyyear,1970‐2014

Thereareanumberofreasonsthataterroristattackmightnotcauseanyfatalities.Onepossibilityisthattheattackwasneverintendedtoharmpeople,butinsteadwasfocusedoncausingonlypropertydamage.Insomecasesgroupscallauthoritiesinadvancetopromptanevacuation.Whilethisstrategywasahallmarkofgroupsactiveinthe1970s,liketheWeatherUnderground,ithasrarelybeenpracticedintheUnitedStatesinrecentyears.Inmanycasesperpetratorstargetunpopulatedareasorinfrastructure,ortargetspacesthataretypicallyoccupied,buttheydosoatnightwhentheareaisvacant.Althoughtheseattacksarenon‐lethal,theyhavethecapacitytocauseextensivepropertydamageandhavelastingeconomicimpacts.Infact,theamountofpropertydamagerecordedintheGTDfornon‐lethalattacksintheUnitedStatestotalsmorethan$233million.Thedamageamountsrangedfrom$50indamagescausedwhenperpetratorsignitedfiresataPlannedParenthoodclinicinCaliforniain2008to$45millionindamagescausedwhentheMacheterosattackedMunizAirNationalGuardbasenearSanJuan,PuertoRicoin1981,destroyingeightfighterjetstoprotestdraftregistration.

0%

10%

20%

30%

40%

50%

60%

70%

Num

ber o

f Att

acks

YearSource: Global Terrorism Database



Asecondreasonanattackmaynotcauseanydeathsisthattheintentwastoharmpeople,butforsomereasonitfailed.Inthesecasesitispossiblethattheattackitselfnevermaterialized—perhapsabombfailedtodetonateorwasdefusedbyauthorities—orthatitwassuccessfullycarriedoutbutdidnothurtanyone,orcausedonlyinjuriesratherthanfatalities.

Figure3:PercentofterroristattacksintheUnitedStatesthatwereunsuccessfulbyyear,1970‐2014

Unsuccessfulattacks—thosethatfailedorwerethwartedeitherwhiletheirperpetratorswereonthewaytoorintheprocessofcarryingthemout—werenotuncommonintheUnitedStates,asshowninFigure3.Between1970and2014,18percentoftheattacksthattookplaceintheUnitedStateswereunsuccessful.Thisistwicetheprevalenceofunsuccessfulattacksworldwide(9%).Thisproportionincreasedslightlyinthe21stcentury,asone‐fifthoftheattacksintheUnitedStatesbetween2000and2014wereunsuccessful,whiletheglobalrateofunsuccessfulattacksduringthesameperiodremainedstableat10percent.Well‐publicizedexamplesofunsuccessfulattacksintheUnitedStatesincludethe2010attempttodetonateexplosivesinTimesSquareinNewYorkCityandthe2009attempttodetonateexplosivesonboardNorthwestAirlinesflight253asitapproachedDetroit,Michigan.In2013and2014,themostrecentyearsforwhichdataareavailable,eightattacks(23%)wereunsuccessful.Threeoftheseinvolvedtheuseofricinbutcausednoillness;threeinvolvedexplosivedevicesthatwereplantedbutdefused—ataNebraskaairport,aprayerchapelinOregon,andaWestVirginiamunicipalbuilding;oneinvolvedanexplosivedevicethatwasmailedtoSherriffJoeArpaioinArizonabutwasdefusedbeforeitdetonated;andanotherinvolvedanattemptedsiegeonacourthouseinGeorgiainwhichtheperpetratorwaskilledbeforehewasabletoenterthecourthouse.Thisremarkablepattern—arelativelylowanddecliningfrequencyofterroristattacks,andespeciallyrarelethalterroristattacks,punctuatedbydevastatingeventswithfar‐reachingimplications—raisesparticularchallengesforthosetryingtounderstandthepotentialthreatofterrorismintheUnitedStates.

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

50%

Num

ber o

f Att

acks

YearSource: Global Terrorism Database



PerpetratorsofTerrorismintheUnitedStatesWecanbegintoexplorethecontextofthesepatternsbyconsideringtheinformationthatwehaveabouttheperpetratorsofattacks.Formorethan80percentoftheattacksthatoccurredintheUnitedStatesbetween1970and2014,someinformationabouttheperpetrator(s)responsiblefortheattackwasavailablefromtheopen‐sourcereports.Fifty‐ninepercentoftheseattackswereattributedto163namedorganizations,whilefor32percenttheinformationwehaveabouttheperpetratorisgeneric,ratherthanreferencingaspecificorganization.4Forexample,thegenericidentifiersusedmostfrequentlytodescribeperpetratorsofattacksintheUnitedStatesbetween1970and2014are“anti‐abortionactivists”(8%ofallattacksinwhichperpetratorinformationwasreported)and“left‐wingmilitants”(8%ofallattacksinwhichperpetratorinformationwasreported).Anadditional9percentofattacksforwhichperpetratorinformationwasreportedwerespecificallyattributedtounaffiliatedindividuals,althoughitisimportanttonotethatthisdesignationhasonlybeensystematicallyusedintheGTDwhencodingattacksthathaveoccurredsince1998.5

Figure4:InformationonperpetratorsofterroristattacksintheUnitedStates,1970‐2014

4Itisimportanttonotethatbecausegenericdesignationsdonotrepresentdiscreteentities,theyoftenoverlap(e.g.,“studentradicals”and“left‐wingmilitants”maydescribethesamepeople).Asaconsequence,statisticsaboutperpetratorsdescribedusingonlygenericidentifiersarenotexhaustiveandshouldbeinterpretedwithcaution.Inaddition,theselabelsdonotrefertocohesivegroups.Theviolentbehaviordiscussedinthisreportwascarriedoutbyextremistsubsetsofbroaderideologicalmovementsandisnotrepresentativeofthebehaviorofthesebroadermovementsmoregenerally.Formanyattacks,genericidentifiersaretheonlyinformationavailableabouttheperpetrators;becauseofthistheyareincludedinthetablesthatfollowtoprovidecontext.5Thisdesignationisusedwhensourcesidentifyanamedperpetratororperpetratorswhoarenotknowntobeactingonbehalfofalargerorganization.Althoughthiscategoryispotentiallyuseful,itisimportanttonotethatterroristactivityperpetratedbyunaffiliatedindividualsmaysometimesbeattributedtogenericorunknownperpetrators,particularlyiftheindividualsarenotnamedinsourcematerials.

UnknownPerpetrator

18%

GenericCharacterization

32% NamedPerpetrator

Organization59%Unaffiliated

Individual9%

SomePerpetratorInformation

Reported82%




Table1:MostactiveperpetratorsofterroristattacksintheUnitedStatesbydecade

1970s 1980s Perpetrator Attacks Percent of

Attacks Perpetrator Attacks Percent of

Attacks Left-Wing Militants 169 13% Anti-Abortion Activists 74 16% Fuerzas Armadas de Liberacion Nacional (FALN) 106 8% Macheteros 31 7% New World Liberation Front (NWLF) 86 7% Jewish Defense League (JDL) 30 7% Black Nationalists 82 6% Omega-7 25 6% Student Radicals 71 6% Organization of Volunteers for the Puerto Rican Revolution 23 5% Weather Underground, Weathermen 45 4% Unaffiliated Individuals 23 5% Jewish Defense League (JDL) 44 3% United Freedom Front (UFF) 19 4% White Extremists 42 3% Army of God 15 3% Black Liberation Army 34 3% May 19 Communist Order 14 3% Chicano Liberation Front 31 2% Fuerzas Armadas de Liberacion Nacional (FALN) 13 3% Armed Revolutionary Independence Movement (MIRA) 31 2%

1990s 2000s6 Perpetrator Attacks Percent of

Attacks Perpetrator Attacks Percent of

Attacks Anti-Abortion Activists 83 26% Unaffiliated Individuals 83 36% Unaffiliated Individuals 55 17% Earth Liberation Front (ELF) 59 26% Animal Liberation Front (ALF) 42 13% Animal Liberation Front (ALF) 42 18% Earth Liberation Front (ELF) 17 5% Anti-Abortion Activists 15 7% Aryan Republican Army 16 5% Coalition to Save the Preserves (CSP) 8 4% The Justice Department 13 4% Al-Qa`ida 4 2% World Church of the Creator 7 2% Revolutionary Cells-Animal Liberation Brigade 2 1% Army of God 6 2% Neo-Nazi Group 2 1% Anti-Government Group 6 2% Sovereign Citizen 2 1% Popular Liberation Army (Puerto Rico) 4 1% White Extremists 2 1% Aryan Liberation Front 4 1% Veterans United for Non-Religious Memorials 2 1% Pedro Albizu Campos Revolutionary Forces 4 1% Minutemen American Defense 1 0% White Extremists 4 1% The Justice Department 1 0% Tehrik-i-Taliban Pakistan (TTP) 1 0% Revenge of the Trees 1 0% Anarchists 1 0% Al-Qa`ida in the Arabian Peninsula (AQAP) 1 0% Ku Klux Klan 1 0%

6Includes2000‐2014throughoutthereport.



Theseaggregatedstatisticsmaskthefactthatthesametypesofperpetratorswerenotcontinuouslyactivefortheentire1970to2014timeperiod.ToprovideabetterunderstandingofthetypesofperpetratorsactiveintheUnitedStatesbetween1970and2014,Table1showsthemostactiveperpetrators,includingnamedorganizations,thosedescribedusinggenericidentifiers,andunaffiliatedindividuals(asacategory),bydecade.Inthe1970s,nearly1,500terroristattackswerecarriedoutintheUnitedStates.Duringthisdecade,morethan100perpetratorswereidentified,includingbothnamedorganizationsandthosedescribedusinggenericidentities.Thelistofperpetratorsthatcarriedoutthemostattacksduringthedecadeismarkedbyleft‐wingextremistgroups,includingorganizationsliketheNewWorldLiberationFront(NWLF),theWeatherUnderground,theBlackLiberationArmy,andtheChicanoLiberationFront,aswellasleft‐wingmilitantsandstudentradicalsnotaffiliatedwithaparticularnamedorganization.Theseperpetratorsemergedasradicalelementsofthecivilrights,feminist,andanti‐warmovementsofthe1960s.Theycarriedoutattacksin35statesandtheDistrictofColumbiainthe1970s,butweremostactiveinCalifornia.Theappearanceofperpetratorsidentifiedas“blacknationalists”and“whiteextremists”onthelistfurtherillustratestheprevalenceofviolencethattookplaceinthecontextofracialconflict.TheFuerzasArmadasdeLiberacionNacional(FALN)andtheArmedRevolutionaryIndependenceMovement(MIRA)wereamongthemostactiveorganizationsusingviolenceintheireffortstosecurePuertoRicanindependence.Finally,theJewishDefenseLeague(JDL),whichwasfoundedinBrooklynin1968,carriedoutdozensofattacksinthe1970s,primarilyinNewYork.Thelistofperpetratorsthatcarriedoutthemostattacksinthe1980sshowsamarkedshiftinthevolumeandideologicalunderpinningsofterrorismintheUnitedStates.ThetotalnumberofnamedorganizationsandperpetratorsidentifiedbygenericdesignationsthatwereattributedresponsibilityforattacksintheUnitedStatesinthe1980sdroppedbelow75,andthenumberofattacksdecreasedbynearlytwo‐thirds(fromnearly1,500inthe1970stojustover500inthe1980s).AlthoughFALNwasstillactive,thefrequencyofitsattacksdecreasedfrommorethan100inthe1970sto13inthe1980s;however,violencecarriedoutbyotherPuertoRicanindependencegroupsbecamemorecommon,includingtheMacheterosandtheOrganizationofVolunteersforthePuertoRicanRevolution.Omega‐7,ananti‐CastroCubangroupthatappearsamongthemostactiveperpetratorsofterroristattacksintheUnitedStatesinthe1980s,wasjustasactiveinthe1970s,butthefrequencyofitsattackswasrelativelylowincomparisontoothergroupsactiveinthe1970s.TheJDLalsoremainedengagedinviolenceinthe1980s,althoughthefrequencyofitsattacksdeclinedsomewhat.Ingeneral,thesharpdeclineinthenumberofterroristattacksintheUnitedStatesinthe1980swaslargelydrivenbydecreasesinattacksbyleft‐wingperpetrators,althoughtheMay19CommunistOrderemergedfromtheremnantsoftheWeatherUndergroundandtheBlackLiberationArmy.Likewise,theUnitedFreedomFront(UFF),aMarxistgroupformedinthemid‐1970s,intensifieditsuseofviolence.Theperpetratorsthatcarriedoutthemostterroristattacksinthe1980swereanti‐abortionactivists,includingthosenotaffiliatedwithanamedgroupaswellasthoseaffiliatedwiththeArmyofGod.Althoughunaffiliatedindividualperpetratorswereamongthemostactiveperpetratorsofterroristattacksinthe1980s,theywerenotactuallyactiveatahigherratethantheyhadbeeninthe1970s.



Inthe1990sthelandscapeofperpetratorsofterroristattacksintheUnitedStatescontinuedtoevolveasthetotalnumberofattacksdeclinedfurthertojustover400andbecameconcentratedamongfewerthan50totalnamedorganizationsandperpetratorsdescribedusinggenericidentities.Infact,morethantwo‐thirdsoftheattackscarriedoutinthe1990swereattributedtoonlysixperpetratordesignations.Thenumberofattacksattributedtounaffiliatedindividualsandgenericallyidentifiedanti‐abortionactivistsincreased,whiletheenvironmentalistgroupsAnimalLiberationFront(ALF),EarthLiberationFront(ELF),andTheJusticeDepartmentappearamongthemostactiveperpetratorsofterroristattacksforthefirsttime.In1995inOklahomaCity,TimothyMcVeighcarriedoutthedeadliestattackintheUnitedStatesupuntilthatpoint.Severalwhitesupremacistgroupswereamongthemostactiveperpetratorsofterroristattacksinthe1990saswell,includingtheAryanRepublicanArmy,theAryanLiberationFront,andtheWorldChurchoftheCreator.TheviolentactivityofthePuertoRicanseparatistgroupslikeFALN,MIRA,andtheMacheterosdeclinedtothepointthattheynolongerappearonthelistofmostactiveperpetratorsinthe1980s.However,thePedroAlbizuCamposRevolutionaryForcesremainedonthelist,albeitwithfourattacks,allofwhichtookplacein1990inPuertoRico.Forsixoftheattacksthatoccurredinthe1990s,theonlyinformationavailableabouttheperpetratorsisthattheywereanti‐governmentextremists.Whileperpetratorsofterroristattacksoftenmaintainanti‐governmentviewstosomedegreeastheyrelatetoaparticulargrievanceorpolicy,theidentityoftheperpetratorsoftheseattackswasmarkedbystrongoppositiontothefederalgovernment,basedeitheronthenatureofthetargetorstatementstheymade.ThreeoftheseattackstargetedInternalRevenueServiceofficebuildings(oneinCaliforniain1992andtwoinColoradoin1997and1999),andtwooccurredinthecontextoftensionsovergovernmentregulationofland,targetingtheBureauofLandManagementin1993theandUnitedStatesForestServicein1995.Thesixthattack,whichtargetedaUnitedStatesDepartmentofLaboremployeeinCaliforniaonApril12,1996,wasprecededbyananonymousphonecalltothevictim’sofficeinwhichthecallerreportedlystated,“Youguysareall[expletive]dead.TimothyMcVeighliveson."Patternsofterroristattacksamongperpetratorsactivebetween2000and2014starklyillustratetheparadoxofmodernterrorismintheUnitedStates.DespitethefactthattheUnitedStatesexperiencedthemostdeadlyseriesofterroristattacksinmodernhistoryinSeptember2001,thetotalnumberofterroristattacksinthe21stcenturydecreasedevenfurtherandbecamemoreconcentratedamongarelativelysmallnumberofnamedorganizations,perpetratorsdescribedusinggenericidentifiers,andunaffiliatedindividuals.Duringthistime,thetotalnumberofterroristattackscontinuedtodeclineto289attacksover15years.Infact,the18perpetratorslistedinTable1representallidentifiedperpetratorsofattacksthattookplacebetween2000and2014.Thetypesofperpetratorsactiveduringthistimeperiodremainedextremelydiverse,andthemostfrequentperpetratorsofterroristattackswereunaffiliatedindividualsofallideologicalpersuasions.Environmentalistgroupsremainedespeciallyactive,asattackswerecarriedoutbytheALF,theELF,theCoalitiontoSavethePreserves,theRevolutionaryCells‐AnimalLiberationBrigade,TheJusticeDepartment,andRevengeoftheTrees.Anti‐abortionactivistsremainedactiveaswellbutcarriedoutfarfewerattacksthantheyhadinthe1980sand1990s.Inadditiontothedeadlyattackscarriedoutbyal‐



Qa’idain2001,operativesfromtheassociatedgroupsTehrik‐i‐TalibanPakistan(TTP)andal‐Qa’idaintheArabianPeninsula(AQAP)conductedunsuccessfulattacksin2009and2010.Thepercentageofattackscarriedoutbyunidentifiedorunaffiliatedperpetratorsisespeciallyhighduringthemostrecentyearsforwhichdataareavailable.Between2012and2014,one‐quarterofthe48attacksrecordedintheGTD(25%)werecarriedoutbyunidentifiedperpetrators,and86percentoftheremainingattackswerecarriedoutbyindividualswhowerenotactingonbehalfofaparticulargroupororganization.Inaddition,oneattack,claimedby“anarchists,”targetedaconstructionsiteinSeattle,WashingtoninFebruary2013.Twootherattacks,inAugustandSeptember2013,wereclaimedbyapreviouslyunknowngroupcallingitself“VeteransUnitedforNon‐ReligiousMemorials,”whichdetonatedexplosivesneartheMingusParkVietnamWarMemorialinCoosBay,Oregon.In2014,twoperpetratorswhoreportedlyself‐identifiedwiththeSovereignCitizenmovementcarriedoutunrelatedattacksinTexasandGeorgia.TheunaffiliatedindividualswhohavecarriedoutterroristattacksintheUnitedStateswereinfluencedbyawidevarietyofmotivations.Furthermore,unlikeorganizations,whoseideologicalrationaleforcarryingoutaparticularattackisoftenexpressedwithgreaterclarity,unaffiliatedindividualsmayhavemotivationsthatwereidiosyncratic,ormulti‐facetedanddifficulttoclassify.Itcanbechallengingtodetermine—oftengivenlimitedinformation—ifcharacteristicsofanindividual’sidentitywerecausallyrelatedtotheattackinquestion,orweremerelycoincidental.Table2summarizeswhatweknowabouttheideologicalmotivationsofoffenderswhowerenotactinginconcertwithaformalorganization.

Table2:Motivesofattackscarriedoutbyunaffiliatedindividualperpetrators,2012‐2014

Date Description/Motive

1/1/2012 An unaffiliated individual carried out four attacks against different targets in New York, New York with Molotov cocktails. He indicated that his motives included "taking out as many Muslims and Arabs as possible." However, sources report that he also had personal grievances with each of the targets.1

4/1/2012 An unaffiliated individual set fire to a Planned Parenthood clinic in Grand Chute, Wisconsin. He indicated that his motive was to "release the souls of the children" who had died in the clinic.2

6/18/2012 An unaffiliated individual attempted to bomb a natural gas pipeline in Plano, Texas. Sources note that the assailant identified as part of the anti-government sovereign movement.3

7/4/2012 and 8/6/2012

An unaffiliated individual carried out arson attacks that damaged and then later destroyed a mosque in Joplin, Missouri. He confessed to the attacks, as well as two others targeting a Planned Parenthood clinic in 2013, but did not specify a particular motive.4

8/5/2012 An unaffiliated individual attacked a Sikh temple in Oak Creek, Wisconsin. The assailant had ties to the white supremacist movement.5

8/15/2012 An unaffiliated individual opened fire on a security guard at the offices of the Family Research Council in Washington, District of Columbia. The assailant stated that he targeted the Family Research Council because of the organization's opposition to gay marriage and gay rights.6

9/30/2012 An unaffiliated individual set a fire at the Islamic Center of Greater Toledo in Perrysburg, Ohio. The assailant indicated that he had acted under the influence of alcohol, "after seeing a wounded U.S. soldier on television, and blamed Muslims for the soldier’s injuries."7



11/30/2012 An unaffiliated individual detonated a small incendiary device at a Social Security Administration building in Casa Grande, Arizona. Sources indicate that the perpetrator was an Iraqi citizen; however, no motive was reported.8

2/7/2013

An unaffiliated individual shot two Riverside police officers in Corona, California, killing one. In a statement posted online, the perpetrator indicated that he was motivated by both his personal frustrations regarding his dismissal from the Los Angeles Police Department as well as what he viewed as excessive use of force and racism in policing.9

4/11/2013 An unaffiliated individual mailed a letter bomb to Sheriff Joe Arpaio of the Maricopa County Sheriff's Office in Arizona. The perpetrator's motive apparently involved attempting to frame a former business partner for the attack.10

5/20/2013 An unaffiliated individual sent letters containing ricin to President Barack Obama, Mayor Michael Bloomberg, and Mark Glaze, Director of Mayors Against Illegal Guns. The sender, who threatened further action against proponents of gun control, was reportedly attempting to frame her estranged husband for the attack.11

11/1/2013 An unaffiliated individual opened fire on Transportation Security Administration (TSA) agents in a terminal at Los Angeles International Airport (LAX), in California. The assailant claimed responsibility for the attack, stating that he wanted to kill and to instill fear in TSA officers.12

4/13/2014 An unaffiliated individual opened fire on civilians outside a Jewish community center and a Jewish retirement home in Kansas City, Kansas. Officials arrested a former Ku Klux Klan member who shouted "Heil Hitler" following the arrest.13

4/27/2014, 6/1/2014, and 6/25/2014

On three separate occasions an unaffiliated individual shot and killed a civilian, twice in Seattle, Washington and once in West Orange, New Jersey. The assailant reportedly aimed to punish the United States for its involvement in Iraq and Afghanistan.14

5/5/2014 An unaffiliated individual planted three explosive devices around the Weirton Municipal Building in Weirton, West Virginia. The perpetrator was reportedly angry with the federal government and "wanted a shootout with the FBI."15

6/8/2014 Unaffiliated individuals shot and killed two police officers eating at a restaurant and killed a bystander at a nearby Walmart in Las Vegas, Nevada. On social media, the assailants decried the federal government, taxes, anti-gun laws, and demanded a revolution.16

9/11/2014

An unaffiliated individual threw two Molotov cocktails at the office of United States Congressman, Emanuel Cleaver, in Kansas City, Missouri. Police described the perpetrator as an anarchist. In a letter confessing to the crime, the assailant stated that the attack was in retaliation for deaths throughout the Middle East and Chile as well as events in Ferguson, Missouri.17

9/12/2014 An unaffiliated individual opened fire on state troopers at the Blooming Grove barracks in Pike county, Pennsylvania, killing one and injuring another. In a letter he wrote to his parents, the perpetrator indicated that he was looking to spark a revolution against the government.18

10/23/2014 An unaffiliated individual attacked a police patrol with a hatchet in New York City, New York, wounding two officers and a bystander. According to the assailant's social media activity, he had recently converted to Islam and was angry about perceived injustices in American society and oppression abroad.19

11/28/2014 An unaffiliated individual opened fire on a federal courthouse, police headquarters, and the Mexican consulate in three separate attacks in Austin, Texas, on the same day. Sources indicate that the incidents were apparently fueled by Christian Identity, anti-government, and anti-immigration sentiments.20

12/20/2014 An unaffiliated individual shot and killed two New York City Police Department officers while they were sitting in their vehicle in New York City, New York. The assailant claimed that the attack was carried out to avenge the deaths of Michael Brown and Eric Garner at the hands of the authorities.21

WhileperpetratorsofterroristattacksintheUnitedStateshaveevolvedovertheyears,somepatternsemergerelatedtolongevity.Table3displaysthe19perpetratordesignationsthatappearinthedatabaseforaspanoflongerthan10years.Unsurprisingly,theonlyperpetratordesignationthatappearsforthefullspanoftheGTD,1970to2014,isunaffiliatedindividuals.Despitethefactthattheseunaffiliatedindividualsarenotlinkedtoeachotherinanyway,itisworthnotingthattheuseofterroristtacticsby



individualsnotlinkedtoaformalorganizationisnotawhollyrecentoccurrence.Thislistisalsomarkedbyperpetratorsdescribedusinggenericidentifiersbecausetheyaremorelikelytopersistovertimeasspecific,likelyunrelatedindividualsandgroupscomeandgo.Asnotedabove,genericperpetratorattributionsarenotmutuallyexclusiveorexhaustive,sothistableprovidesageneralunderstandingoftheiractivitybutisnotcomprehensive.

Table3:PerpetratorsofterrorismintheUnitedStatesactivelongerthan10years,1970‐2014

Perpetrator Attacks Fatalities Start Year End Year Span Unaffiliated Individual(s) 187 272 1970 2014 44 Ku Klux Klan 23 7 1970 2008 38 Neo-Nazi Group 9 2 1970 2008 38 White Extremists 52 9 1970 2004 34 Anti-Abortion Activists 182 4 1977 2008 31 Cuban Exiles 21 0 1970 1996 26 Animal Liberation Front (ALF) 90 0 1987 2011 24 Jewish Extremists 8 0 1974 1997 23 Puerto Rican Nationalists 28 0 1970 1991 21 Macheteros 37 6 1978 1998 20 Anti-Castro Group 3 0 1978 1994 16 Army of God 21 3 1982 1998 16 Jewish Defense League (JDL) 74 4 1970 1986 16 Black Liberation Army 36 19 1970 1984 14 Earth Liberation Front (ELF) 76 0 1995 2009 14 Anti-Government Group 7 0 1986 1999 13 Aryan Nation 6 0 1986 1999 13 Mujahedin-e Khalq (MEK) 2 0 1981 1992 11 The Justice Department 14 0 1999 2010 11

GenericallyidentifiedperpetratorsthathavecarriedoutattacksintheUnitedStatesforatleast20yearsincludeneo‐Nazis,whiteextremists,anti‐abortionactivists,Cubanexiles,Jewishextremists,andPuertoRicannationalists.Attacksattributedtoanti‐Castroperpetratorsspanned16years,andattacksattributedtoanti‐governmentperpetratorsspanned13years.Thelongest‐lastingnamedperpetratororganizationsincludetheKuKluxKlan,theALF,theMacheteros,ArmyofGod,theJewishDefenseLeague,theBlackLiberationArmy,theELF,AryanNations,Mujahedin‐eKhalq,andTheJusticeDepartment.Althoughtheseperpetratorsshareincommonthattheypersistedincarryingoutterroristattacksformorethan10years,thevolume,concentration,andimpactoftheiractivityvaries.Amongtheseperpetrators,anti‐abortionactivistscarriedoutthehighestnumberofattacksperyear(5.9),whileseveralgroupscarriedoutveryfewattacksthatwereseparatedbylongperiodsofinactivityintheUnitedStates.

SpatialPatternsofTerrorismintheUnitedStatesAlthoughterroristattackshaveoccurredinall50states,theDistrictofColumbia,andPuertoRico,theyhavebeenespeciallyprevalentincertainlocations.Infact,halfofallattacksintheUnitedStatesbetween1970and2014tookplaceinCalifornia(22%),NewYork(19%),andPuertoRico(9%).Figure5illustratesthegeographicdistributionofterroristattacksintheUnitedStates,showinginparticulartherelativeconcentrationofcasualties(fatalitiesandinjuries)causedbytheattacks.



Itisimportanttonotethatwhilefatalitiesareuniformlymeasuredaslossoflife,injuriescanvaryagreatdealwithrespecttoseverityandimmediacy.Forexample,Figure5includesalargeredmarkerinOregonbecauseofa1984attackinwhichmorethan700individualsbecameillwithfoodpoisoningaftermembersoftheRajneeshcultcontaminatedsaladbarsinrestaurantswithSalmonellainanattempttoinfluencelocalelections.Incontrast,the2014attacktargetingtheBostonMarathonwoundedmorethan260people,andinvolvedrelativelyminorinjuriessuchasshort‐orlong‐termdamagetohearing22aswellassevereinjuriesincludinglossoflimbs.23ItisespeciallydifficulttoquantifytheinjuriescausedbytheattacksonSeptember11,2001inNewYorkCity.Infact,duetoalackofareliableestimateforthenumberofpeoplewoundedasaresultoftheattacksontheWorldTradeCenter,theGTDrecords“unknown”ratherthanaparticularvalue,andtheyareexcludedfromFigure5.Inadditiontotheinjuriesthatoccurredonthedayoftheattack,epidemiologicalanalysesindicatethatthelong‐termhealthimpactsonfirstrespondersandotherresidentswereconsiderable,particularlywithrespecttopost‐traumaticstressdisorder,respiratoryillnesses,heartdisease,andotherillnesses.24

Figure5:CasualtiesofterrorismintheUnitedStates,1970‐2014

TheoverallgeographicconcentrationofattacksintheUnitedStatesisdrivenlargelybypatternsinthe1970sand1980s,whenthevastmajorityofattackstookplace.Infact,asTable4shows,inthe1970sanevengreaterconcentration(59%)ofallattackstookplaceinCalifornia,NewYork,andPuertoRico.Althoughthisgeneralpatterncontinuedinthe1980s,whenmorethanone‐fifthofallattacks(21%)werelocatedinPuertoRico(followedby18percentinNewYorkand14percentinCalifornia),itchangedconsiderablyinthe1990s.Asdiscussedabove,thenumberofterroristattackscarriedoutbyPuerto



Ricannationalistgroupsdeclinedinthe1990s,particularlyinPuertoRico.AtthattimeterrorismintheUnitedStatesbecamemuchmoregeographicallydispersed.Despitethefactthatthenumberofattackshaddeclineddramatically,45states,theDistrictofColumbia,andPuertoRicoexperiencedattacks.Thestateswiththemostattacks:California(18%),NewYork(7%),andFlorida(6%)experiencedlessthanone‐thirdofallattacksintheUnitedStatesduringthe1990s.Thepatternbetween2000and2014wassimilar,howeverasidefromthelong‐establishedconcentrationsinCalifornia(18%)andNewYork(10%),thegeographicconcentrationattackswasfurtherdiminished.ThenumberofattacksinFloridadeclinedby50percentbetweenthe1990sand2000s,whileterrorisminWashington(State)becamemoreprevalentduelargelytotheactivityoftheEarthLiberationFront(8attacks),theAnimalLiberationFront(2attacks),andagroupcalledRevengeoftheTrees(1attack).BecausethenumberofterroristattacksintheUnitedStateswasrelativelylowbetween2000and2014,isolatedstringsofrelatedattacksinaparticularstateinfluencetheoveralldistributionoflocationsconsiderably.

Table4:U.S.Statesexperiencingthemostterroristattacksbydecade,1970‐2014

1970s Attacks Killed % Attacks 1980s Attacks Killed % Attacks California 397 46 27% Puerto Rico 106 7 21%

New York 348 43 24% New York 91 5 18%

Puerto Rico 122 15 8% California 70 8 14%

Illinois 76 4 5% Florida 41 0 8%

Florida 70 6 5% District of Columbia 20 1 4%

1990s Attacks Killed % Attacks 2000s Attacks Killed % Attacks California 61 3 16% California 49 5 17%

New York 28 6 8% New York 31 2767 11%

Florida 22 7 6% Washington 21 4 7%

Oregon 21 0 6% Arizona 14 2 5%

Puerto Rico 17 0 5% District of Columbia 12 5 4%

WeaponsUsedinTerroristAttacksintheUnitedStatesPatternsofweaponusageinterroristattacksintheUnitedStateshavealsoevolvedovertime.Table5showsthetypesofweaponsusedinterroristattacksbetween1970and2014,whileFigure6illustrateshowthesetrendschangedbydecade.NotethattheGTDrecordsuptofourdifferentweaponsforeachattack,sothenumberofweaponsusedisgreaterthanthenumberofattacks.Overall,thevastmajority(93%)ofallweaponsusedinterroristattacksintheUnitedStateswereexplosives,incendiaries,orfirearms.Ofthesethreetypesofweapons,explosivesweremostcommonlyusedinattackstargetingmanytypesoftargets,includingutilities(82%),airportsandaircraft(79%),telecommunicationsystems(78%),andtransportation(73%).Incendiariesweremostcommonlyusedinattacksagainstabortion‐relatedtargets(73%),non‐governmentalorganizations(NGOs;54%),andreligiousfiguresandinstitutions(41%).Firearmswereusedastheprimaryweaponinonly13percentofattacks,andwerenotthemostcommonlyusedtypeofweaponforanyparticulartypeoftarget.



Incontrasttotheseweapontypes,whicharefairlyeasytoaccess,asmallnumberofattacksinvolvedtheuseofmoreunusualtypesofweapons,includingsomethatarefairlyeasytoattainandothersthataremoredifficult.Forexample,32attacksintheUnitedStates,includingthoseon9/11,involvedmeleeastheprimarymeansofattack.Theseeventstypicallyinvolvesometypeofhand‐to‐handcombat,particularlyincludingknivesorothersharpobjects.Ofcourse,theextremelydeadlyuseofmelee‐typeweaponsbythe9/11hijackersisunique—asidefromthefourattackson9/11,eightoftheattacksinvolvingmeleeasaprimaryweaponwerelethal,eachresultinginonedeath.

Table5:TypesofweaponsusedinterroristattacksintheUnitedStates,1970‐2014

Weapon Type Weapon Uses % of Weapon Uses Explosives/Bombs/Dynamite 1402 52% Incendiary 811 29% Firearms 390 13% Melee 55 1% Sabotage Equipment 39 1% Biological 24 1% Other 24 1% Fake Weapons 17 1% Chemical 13 <1% Vehicle (excluding VBIEDs) 9 <1% Radiological 1 <1%

Note: The type of weapon used was unknown in 2 percent of all attacks.

Likemelee‐styleweapons,sabotagetoolsarerelativelyeasytoobtainbuthavebeenusedveryinfrequentlyinterroristattacksintheUnitedStates.Sabotageequipment,mostcommonlyusedinfacility/infrastructureattackstargetingutilities,typicallycausesprimarilyeconomicharmbutalsohasthecapacitytocausecasualtieswhentheperpetratorsintendtodoso.Forexample,oneoftheterroristattacksthatcausedthemostinjuriesintheUnitedStateswascarriedoutin1995whenperpetratorscallingthemselves“SonsoftheGestapo”sabotagedtraintrackscausinganAmtrakpassengertraintoderailinArizona,killingonepersonandwoundingmorethan75others.Inlessthan1percentofattacksintheUnitedStates,perpetratorsusedvehiclesthemselvesasweapons.Thistypicallyinvolvesdrivinganautomobileorflyingaplaneintoabuildingoracrowdofpeopleanddoesnotincludevehicle‐borneimprovisedexplosivedevices—VBIEDs.Themostrecentexampleofthisoccurredin2010,whenJosephStackflewhisprivately‐ownedplaneintoanInternalRevenueServicebuildinginAustin,Texas.Theimpactignitedafireintheseven‐storybuilding,killedStackandoneIRSworker,andwoundedmorethan10others.Theuseofbiological,chemical,andradiologicalweaponsinterroristattacksbetween1970and2014intheUnitedStateswasalsoextremelyrare.Thefirstbiologicalattacksduringthistimeperiodwerethe1984attacksmentionedaboveinwhichfollowersoftheRajneeshcultattemptedtoimpactlocalelectionsinTheDalles,OregonbycontaminatingsaladbarswithSalmonella,causinghundredsofresidentsto



becomeill.However,halfofallbiologicalattacksintheUnitedStatesbetween1970and2014(12outof24)tookplaceinOctoberandNovemberof2001whenaseriesofattacksinvolvedanthraxsentthroughthemailtonumerousrecipients,includingprimarilygovernmentandmediatargets.Thirteenattacksinvolvingchemicalweaponstookplacebetween1970and2014,andtheweaponsusedincludedcyanide,nervegas,pepperspray,teargas,andacid.Theseattackstypicallycausedinjuriesbutnodeaths.Forexample,membersoftheJewishDefenseLeaguecarriedoutanattackwithateargasgrenadein1986attheMetropolitanOperaHouseatLincolnCenterinNewYorkCity,injuringapproximately30people.TheonlyterroristattackintheUnitedStatesinvolvingchemicalweaponsthatwaslethalwasthe1973assassinationofMarcusFoster,thefirstblacksuperintendentofOaklandSchools.Fosterwasshoteighttimeswithbulletslacedwithcyanide;however,sourcesindicatethathediedfromthebulletwounds,notthecyanide.TheSymbioneseLiberationArmyclaimedresponsibilityfortheattack.25Finally,theonlyrecordeduseofradiologicalweaponsintheUnitedStatesoccurredin1985whenunidentifiedperpetratorsattemptedtocontaminatethewatersupplyservingNewYorkCitywithplutonium.Althoughofficialstestedthedrinkingwateranddetectedincreasedlevelsofplutonium,theattackwasunsuccessfulbecausetheconcentrationwasnotgreatenoughtocausephysicalharmtoresidents.26InterestingpatternsemergewithrespecttotheuseofweaponsinterroristattacksintheUnitedStates.Inthe1970s,themajorityofweapons(63%)wereexplosives,whileone‐quarter(25%)wereincendiaryweapons(e.g.,arson,Molotovcocktails).Theuseofexplosivesdroppeddramaticallyfrommorethan900usesinthe1970stofewerthan70between2000and2014.Theuseoffirearmsdeclinedaswell,thoughatlessthanhalfthemagnitudeofexplosives(firearmswereusedin186attacksinthe1970sand43attacksbetween2000and2014).Whiletheuseofincendiaryweaponsdeclinedbetweenthe1970sandthe1980s,itactuallyincreasedinthe1990sanddecreasedonlyslightlyinthe21stcentury.Finally,attackscarriedoutusing“other”typesofweaponswererarebutincreasedconsistentlyovertime.7Inparticular,trendsinthiscategoryaredrivenbythe500percentincreaseintheuseofbiologicalweaponsbetweenthe1980s(4attacks,involvingSalmonella)andthe2000s(20attacks,primarilyinvolvingricinandanthrax).TheseabsolutechangesinattackpatternsproducetherelativedistributionsshowninFigure6.AsthenumberofterroristattacksdeclinedintheUnitedStates,therelativefrequencyofattacksinvolvingincendiaryweaponsmorethandoubled,whiletherelativefrequencyofattacksinvolvingexplosivesdecreasedbytwo‐thirds.Therelativefrequencyofterroristattacksinvolvingfirearmsinitiallyincreasedinthe1980sand1990s,butdecreasedslightlyinthe2000s.

7The“other”categoryinFigure6andFigure7includes:biologicalweapons,chemicalweapons,fakeweapons,radiologicalweapons,sabotageequipment,andvehicularweapons(excludingVBIEDs),eachofwhichwereusedinlessthan1percentofattacksintheUnitedStates.



Figure6:WeaponsusedinterroristattacksintheUnitedStates,bydecade

Note:Thetypeofweaponusedwasunknownin2percentofallattacks.TheweaponsusedinterroristattacksintheUnitedStatesdifferdistinctlyfromworldwidetrends.WhileexplosivesarethemostcommontypeofweaponusedinterroristattacksbothintheUnitedStatesandglobally,perhapsmostnotably,terrorismintheUnitedStatesismarkedbyadisproportionateuseofincendiaryweapons,suchasarsonandfirebombs.Specifically,theprevalenceofincendiariesusedinterroristattackswas3.75timeshigherintheUnitedStatescomparedtoworldwidepatterns.Incontrast,theuseoffirearmsinterroristattackswas2.63timesmoreprevalentworldwide,comparedtotheUnitedStates.

22%25%

46% 48%

63% 52%

25% 21%

12%

17%

17%14%

1% 4%

10%13%

2% 1% 2% 4%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

1970s 1980s 1990s 2000s

Perc

ent o

f all

Wea

pons

Decade

Melee

Other

Firearms

Explosives/Bombs/Dynamite

Incendiary




Figure7:WeaponsusedinterroristattacksintheUnitedStatesandglobally,1970to2014

Note:Thetypeofweaponusedwasunknownin2percentofallattacksintheUnitedStatesand8percentofallattacksworldwide.

TargetsofTerroristAttacksintheUnitedStatesAsshowninTable6,terroristattacksintheUnitedStateshavetargetedawidevarietyofentities,butthemostcommontargetsbetween1970and2014werebusinesses(28%),followedbynon‐diplomaticgovernmenttargets(13%),andprivatecitizensandproperty(12%),whichcomprisemorethanhalfofalltargetsattacked.TheGTDfurtherclassifiestypesoftargetsintosubtypes,whichprovideamoredetailedsummaryoftargetingpractices.BusinesstargetsintheUnitedStatesweremostcommonlybanks/commerce(30%),retail(23%),ormultinationalcorporations(10%).Bankswereoftentargetedinattacksbyextremeleft‐wingperpetrators,especiallyintheearly1970s.Atthattime,retailstoreswerealsotargetedbythesegroupsbecauseoftheircommercialsymbolismandthepotentialimpacttotheeconomy.Morerecently,violentattacksagainstretailstoressuchasthosethatsellfur,leather,ormeat

50% 52%

29%

8%

14%

37%

5% 1%2% 3%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

United States Worldwide

Perc

ent o

f all

Wea

pons

Melee

Other

Firearms

Incendiary

Explosives/Bombs/Dynamite




werecarriedoutbyanimalrightsgroups.Awidevarietyofmultinationalcorporationsweretargeted,mostbasedintheUnitedStates,includingoilcompanies,conglomerates,technologycompanies,andautomotivecompanies.

Table6:TargetsofterroristattacksintheUnitedStates,1970‐2014

Target Type Number of

Targets Attacked % Targets Business 771 28%

Government (Non-Diplomatic) 353 13%

Private Citizens & Property 326 12%

Abortion Related 262 9%

Military 185 7%

Educational Institution 172 6%

Police 167 6%

Government (Diplomatic) 144 5%

Religious Figures/Institutions 90 3%

Utilities 87 3%

Airports & Aircraft 76 3%

Journalists & Media 58 2%

NGO 30 1%

Transportation 16 1%

Tourists 12 0%

Telecommunication Systems 10 0%

Terrorists/Non-State Militia 8 0%

Food or Water Supply 7 0%

Maritime Vessels 7 0%

Violent Political Party 6 0% Note: The type of target was unknown in 0.5 percent of attacks.

Themajorityofnon‐diplomaticgovernmenttargets(61%)werefederal,state,local,andtribalgovernmentbuildingsandfacilities.ThesetargetsincludedtheInternalRevenueService(IRS),theFederalBureauofInvestigation(FBI),thePentagon,cityhalls,theBureauofLandManagement,andvariousotherfederalbuildingsincludingtheAlfredP.Murrahbuilding,attackedinOklahomaCityin1995.Themostcommonlytargetedgovernmentfacilitiesbetween1970and2014wereSelectiveServiceoffices,whichwerebombedandburnedbyanti‐warperpetratorsinthe1970s.Anadditional14percentofnon‐diplomaticgovernmenttargetswereassociatedwiththejudicialsystem(judges,attorneys,andcourts),and11percentwerepoliticiansandpoliticalparties/functions.Themostcommontargetsintheprivatecitizensandpropertycategorywereindividualswhowereattackedbasedontheirraceorethnicity(21%).Anadditional15percentofattackstargetingprivatecitizensandpropertyweredirectedatresidences.Othertypesoftargetsinthiscategoryincludedthose



relatedtolaborunionsorspecificoccupations(15%);publicspacessuchasparks,museums,monuments,orplazas(12%);vehicles(5%);politicalpartymembersorpoliticalrallies(5%);andindividualstargetedbasedontheirreligion(1%).Attacksonabortion‐relatedtargetscomprised9percentofallattacksbetween1970and2014intheUnitedStates,andtheseattackscomprised96percentofallattacksonabortion‐relatedtargetsworldwide.Thevastmajorityofattacksonabortion‐relatedtargetswerenon‐lethal(96%),and94percenttargetedclinicsorfacilities,while6percentofattackstargetedabortionprovidersorpersonnel.Morethanhalfofallattacksonmilitarytargets(54%)tookplacein1970and1971,priortotheendofU.S.militaryinvolvementintheVietnamWar.However,attacksonmilitarytargetsintheUnitedStateshaveoccurredineachdecadesincethen.Smallpeaksinthenumberofattacksonmilitarytargetstookplacein1979,whenPuertoRicannationalistsincludingmembersofFALNandRevolutionaryCommandosofthePeople(CRP)carriedoutmorethan10bombingsandassaultsinPuertoRicoandChicago,andin1986,whentheMacheteros,theOrganizationofVolunteersforthePuertoRicanRevolution,andtheArmedForcesofPopularResistance(FARP)attemptedaseriesofbombingstargetingrecruitingofficesandothermilitarytargetsinPuertoRico.Theseattacks,mostofwhichwereunsuccessfulbecausethehomemadedevicesfailedorwerediscovered,wereintendedtoprotestplanstotrainNicaraguanContrasinPuertoRico.Whileeightofthe10attacksonmilitarytargetsinthe1990stookplaceinPuertoRico,eightofthenineattackstargetingthemilitarybetween2000and2014occurredontheU.S.mainland.PerhapsmostnotableamongtheseisthearmedassaultcarriedoutbyMajorNidalHasanin2009atFortHood,inKilleen,Texas,whichkilled13andwoundedmorethan30others.ManyoftheterroristattacksoneducationalinstitutionsintheUnitedStates(64%)occurredduringthe1970sandfrequentlyinvolvedbombingsandfirebombingsatuniversities.Theseattacksweretypicallycarriedoutbyperpetratorsidentifiedas“studentradicals”andotherleft‐wingextremistsinoppositiontotheVietnamWarandperceivedracialinequitiesineducation.Beginninginthe1980s,attacksoneducationalinstitutionswereincreasinglycarriedoutbyenvironmentalgroupstargetingpersonnelandinfrastructuretoprotestscientificresearchandtestingonanimalsandgeneticallymodifiedplants.Between1970and2014,78percentofallattacksoneducationalinstitutionstargetedfacilities,while22percenttargetedteachers,professors,orotherpersonnel.AlthoughterroristattacksintheUnitedStateswereconcentratedinthe1970soverall,thisisespeciallytrueofattackstargetingthepolice.Infact,85percentofallterroristattacksagainstthepolicetookplaceinthe1970s.Morethanhalfoftheseattacks,whichweretypicallyarmedassaultsorbombings,werespecificallyattributedtotheBlackLiberationArmy,theBlackPanthers,orBlacknationalistsnotaffiliatedwithaspecificorganization.Between2000and2014,therewere10attacksthatprimarilytargetedpoliceintheUnitedStates,andsixofthemtookplacein2014.InJune2014,JeradandAmandaMillerkilledtwopoliceofficersandabystanderinLasVegas,Nevada.Onsocialmedia,theassailantsreportedlydecriedthefederalgovernment,taxes,anti‐gunlaws,and



demandedarevolution.InAugust2014,DouglasLeguinopenedfireonfirefightersandpoliceofficersrespondingtoa911callhemadeinDallas,Texas,thoughnocasualtieswerereported.SourcesindicatethatLeguinself‐identifiedaspartoftheSovereignCitizenmovement.InSeptember2014,EricFreinshottwostatetroopersinPikeCounty,Pennsylvania,killingoneandwoundingtheother.Freinindicatedthatheintendedtosparkarevolutionagainstthegovernment.InOctober2014,ZaleThompsonwoundedtwopoliceofficerswhenheattackedthemwithahatchetinNewYorkCity,NewYork.AccordingtoThompson’ssocialmediaactivity,hehadrecentlyconvertedtoIslamandwasangryaboutperceivedinjusticesinAmericansocietyandoppressionabroad.InNovember2014,LarryMcQuilliamsopenedfireonpoliceheadquartersinAustin,Texas,causingnocasualties.SourcesindicatethatMcQuilliamswasmotivatedbyanti‐governmentandanti‐immigrationsentiments.InDecember2014,IsmaaiylBrinsleykilledtwopoliceofficersinNewYorkCity,NewYork.BrinsleyindicatedthattheattackwascarriedoutinretributionforthedeathsofMichaelBrownandEricGarneratthehandsofpoliceofficers.AttacksondiplomatictargetsintheUnitedStatestargeted39differentnationalitiesandtheUnitedNations.DiplomaticentitiesfromtheSovietUnionexperiencedasmanyterroristattacksintheUnitedStates(21attacks)asthenexttwonationalitiescombined—Turkish(11attacks)andinternationaltargets(10attacks,allagainsttheUnitedNations).TheseattacksonSovietdiplomatictargets,whichalltookplaceinthe1970sandearly1980s,werealmostallcarriedoutinNewYorkbytheJewishDefenseLeague,JewishDirectAction,ThunderofZion,andtheUnitedJewishUnderground.Between1990and2014,seventerroristattacksintheUnitedStatestargeteddiplomaticentities—threetargetedtheUnitedNations,andtheotherstargetedtheSouthKoreanconsulateinSanFrancisco,andtheBritishandMexicanconsulatesinNewYorkandTexas.OutofallattacksondiplomatictargetsintheUnitedStates,52percenttargeteddiplomaticfacilitiessuchasembassiesandconsulates;31percenttargeteddiplomaticpersonnel;and17percenttargetedtheUnitedNationsorspecificUNMissions.Attacksonutilitiesfrequentlytargetedelectricalfacilities(88%),ratherthanoil(9%),orgas(3%).Morethan83percentofattacksonutilitiesinvolvedexplosives,andalthoughnoneresultedinfatalities,thevalueofpropertydamagesrangedfrom$500whentheNewWorldLiberationFront(NWLF)carriedoutanincendiaryattackonanelectricaltowerinCaliforniain1975to$600,000whenunidentifiedperpetratorsdestroyedanelectricaltransformerinFloridawithdynamitein1970.AttacksonreligiousentitiesintheUnitedStatestargetedavarietyofreligions,includingChristian,Muslim,HareKrishna,Hindu,Jewish,andSikhfiguresandinstitutions.Themajorityoftheseattacks(79%)involvedexplosivesorincendiaryweapons,and78percenttargetedplacesofworshiporaffiliatedinstitutions,while22percenttargetedreligiousfigures,includingimams,ministers,reverends,priests,andotherreligiousleaders.OneofthemostdeadlyterroristattacksinrecenthistoryintheUnitedStatesoccurredin2012,whenWadeMichaelPageopenedfireataSikhtemple,killingsevenpeopleandwoundingfour.Page,awhitesupremacist,wasshotbyapoliceofficerinthewakeoftheattackandkilledbyaself‐inflictedgunshotwound.AttacksonairportsandaircraftwerequiterareintheUnitedStates—comprisingonly3percentofalltargets—buttheycertainlyhavethepotentialtobedevastatingintermsofbothlossoflifeandeconomic



impacts.Althoughattacksonairportsandaircraftweremostcommoninthe1970sand1980s(43attacksand23attacks,respectively),theydeclinedtoonlytwoattacksinthe1990s—involvinganexplosivedevicethatwasdefusedatSanFranciscoInternationalAirportandasmallbombthatdetonatednearLaGuardiaAirport.Fromthe1990stothe2000s(2000to2010)thenumberofattacksonairportsandairlinestripled,includingthefourattacksonplaneson9/11,a2002shootingattheIsraeliElAlticketcounteratLosAngelesInternationalAirport(LAX)thatkilledtwopeopleandwoundedfourothers,andthe2009attemptedbombingofNorthwestFlight253fromAmsterdamtoDetroit,claimedbyalQa’idaintheArabianPeninsula(AQAP).In2013thereweretwoattackstargetingairportsintheUnitedStates.InAprilanexplosivedevicewasdefusedatanairportinNebraska,andinNovemberagunmantargetingtheTransportationSecurityAdministration(TSA)shotandkilledaTSAofficeratLAX.ThekidnappingandmurderofjournalistsoutsidetheUnitedStateshaverecentlyraisedtheprofileoftherisksfacedbymediapersonnelinconflictregions;however,terroristattacksintheUnitedStatesrarelytargetedjournalistsandmedia.AttacksonjournalistsandmediaintheUnitedStatesweremostcommoninthe1970sand1980s.Inthe1970snearlythree‐quartersofallattacksonmediawerebombings,whileinthe1980s,bombingsdeclineddramaticallyandincendiaryattacksonmediafacilitiesandassassinationsofhigh‐profile,outspokenmediatargetscomprisednearlythree‐quartersofattacksonjournalistsandmedia.TheonlykidnappingofamediatargetintheUnitedStateswasthe1974abductionofPatriciaHearstbytheSymbioneseLiberationArmyinordertomakedemandsofherfather,headoftheHearstmediacorporation.Duringtheperiodfrom2000to2014attacksonmediatargetstookaconsiderablydifferentform.Sevenattackstookplaceduringthistimeperiod,fiveofwhichoccurredinOctober2001duringtheseriesofanthraxattacksdiscussedabove.ThetargetsoftheseattacksincludedAmericanMedia,inBocaRaton,Florida;NBC,ABC,andCBSNews,allinNewYorkCity;andtheNewYorkPost.Thesixthattackoccurredin2010whenradicalenvironmentalistJamesLeetookthreepeoplehostageattheDiscoveryCommunicationsheadquartersbuildinginSilverSpring,Maryland.Leewasarmedwithstarterpistolsandcrudeexplosivedevicesstrappedtohisbody.Afterfourhours,thehostagesituationendedwhenpolicesnipersshotandkilledLee.Finally,theseventhattacktargetedaphotojournalistpresentingaphotographyexhibitontheconflictinUkraineatanartgalleryinNewYorkCity,NewYork.AttacksonNGOs;transportation;tourists;telecommunicationsystems;terroristsornon‐statemilitias;thefoodorwatersupply;maritimevessels;andviolentpoliticalparties(definedasorganizationsthatengageinbothelectoralpoliticsandterrorism)wereextremelyrareintheUnitedStates.Eachcomprisedlessthan2percentoftargetsofterrorismintheUnitedStatesbetween1970and2014.AsshowninTable7,despitethefactthattherewerefarfewerterroristattacksbetween2000and2014thanthepreviousthreedecadesintheUnitedStates,thetargetsoftheseattackswereextremelydiverse.Morethan2,600attackson20differenttypesoftargetsintheUnitedStatestookplaceduringtheentiretimespancoveredbytheGTD,and18differenttypesoftargetswereattackedinthe289incidentsthatoccurredbetween2000and2014.Theproportionofattackstargetingbusinessesremainedfairlyconsistentwiththegeneralpattern;however,attacksonprivatecitizensandpropertyweremorethan



twiceasprevalentbetween2000and2014,andattacksonnon‐diplomaticgovernmenttargetswerenearly50percentmoreprevalentduringthistimeperiod.Attacksonabortion‐relatedtargets,themilitary,andpolicewerelessprevalentfrom2000to2014,whiletheproportionoftargetsthatwerereligiousfiguresandinstitutionswastwiceashighasthetrendforthefulltimespan.

Table7:TargetsofterroristattacksintheUnitedStates,2000‐2014

Target Type Number of

Targets Attacked % Targets Business 82 25%

Private Citizens & Property 75 23%

Government (Non-Diplomatic) 57 17%

Abortion Related 20 6%

Educational Institution 18 6%

Religious Figures/Institutions 18 6%

Police 11 3%

Military 10 3%

Airports & Aircraft 8 2%

Journalists & Media 7 2%

NGO 4 1%

Transportation 4 1%

Government (Diplomatic) 4 1%

Utilities 4 1%

Telecommunication Systems 1 0%

Terrorists/Non-State Militia 1 0%

Tourists 1 0%

Note: The type of target was unknown in 1.4 percent of attacks.Inmanycases,terroristattacksintheUnitedStatestendedtotargetbuildingsorinfrastructureratherthanspecificpeopleorpersonnel.Forexample,aswenotedabove,78percentofallattacksoneducationaltargetswereaimedatschools,universities,oreducationalbuildingsratherthanisolatedteachers,professors,instructors,orotherpersonnel.Bearinginmindthatthesedistinctionsaresomewhatlooselydefinedbecausepeopleareofteninsidebuildingsastheyareattacked,Figure8showsthedistributionbetweenthesetwogeneraltargetingstrategiesforattacksonthosetypesoftargetsforwhichwecouldmakethisdetermination.Certaintypesoftargets,suchasthefoodorwatersupply,telecommunicationsystems,transportation,andutilities,werebothinfrequentlyattacked(makingpercentagessomewhatsensitivetovariation)andessentiallybydefinitioninvolveinfrastructureratherthanspecificpeopleorpersonnel.Therefore,100percentofattacksonthesetargetswerefocusedonbuildingsorinfrastructure.Oftheremainingtargettypes,onlyattacksonpoliceweremorelikelytobeaimedatpeopleorpersonnelratherthanbuildingsorinfrastructure.



Figure8:TargetsofterrorismintheUnitedStates:

Buildings/infrastructurevs.people/personnel,1970‐2014

ConclusionsThepatternsofterrorismintheUnitedStatesillustratethatthethreatofterrorismisfarfromuniform.AlthoughterrorismintheUnitedStateswasmostcommoninthe1970sandisrarelylethal,therearecertainlycriticalexceptionstothisgeneraltrend,includingthedevastatingmasscasualtyattacksinOklahomaCityin1995andinNewYork,Pennsylvania,andVirginiaonSeptember11,2001.Thisunusualpattern,alongwiththefactthatnumerousunsuccessfulattackswereattemptedintheUnitedStates,presentsuniquecounterterrorismchallenges.Inthe1970s,1980s,and1990s,certainpatternsemergedregardingtheperpetratorsofterrorismintheUnitedStates,themovementstheyrepresented,andthetacticstheyadopted.However,inthefirst14yearsofthe21stcentury,perpetratorsandtargetsintheUnitedStateswereespeciallyvariedandsomewhatlesspredictable.Attackswerefrequentlycarriedoutanonymously,organizationsrarelyclaimedresponsibilityforattacks,andperpetratorswereofteneitherunidentifiedorunaffiliatedwithaformallyorganizedgroup.TerroristattacksintheUnitedStatesbetween2000and2014wererelativelyinfrequentcomparedtoearlierdecades,buttheywereextremelydiversewithrespecttolethality,perpetratormotivation(whichcanbeinferredfromeithertheidentificationoftheperpetratororthesymbolismofthetarget),location,typesofweapons,andtypesoftargets.

0% 20% 40% 60% 80% 100%

Utilities

Transportation

Tourists

Telecommunication Systems

Religious Figures/Institutions

Police

Government (Non-diplomatic)

Government (Diplomatic)

Food or Water Supply

Educational Institution

Abortion Related

Percent of Attacks within Target Type

Buildings/Infrastructure People/PersonnelSource: Global Terrorism Database



Endnotes

1Long,C.(2012,January5).SuspectedQueensfirebomberarraignedonarson,hatecrimecharges.AssociatedPress/NBCNewYork.RetrievedNovember12,2015,fromhttp://www.nbcnewyork.com/news/local/Suspect‐Firebomb‐Molotov‐Cocktail‐Arson‐Arraign‐Bomb‐Attack‐136726193.html2Flynt,J.(2012,July8).JuryfindsFrancisGradyguiltyofsettingfiretoPlannedParenthoodclinic.WTAQ.RetrievedNovember12,2015,fromhttp://wtaq.com/news/articles/2012/jul/09/trial‐begins‐for‐kaukauna‐man‐accused‐of‐setting‐fire‐to‐planned‐parenthood3MacNab,J.(2012,July3).SovereignextremistinjuredinTexasbombexplosion.Forbes.RetrievedNovember12,2015,fromhttp://www.forbes.com/sites/jjmacnab/2012/07/03/sovereign‐extremist‐injured‐in‐texas‐bomb‐explosion4Murphy,K.(2013,October22).ManconfessestoMissourimosqueandclinicfires,prosecutorssay.Reuters.RetrievedNovember12,2015,fromhttp://www.reuters.com/article/2013/10/22/us‐usa‐crime‐missouri‐idUSBRE99L04A201310225Goode,E.andS.F.Kovaleski.(2012,August6).Wisconsinkillerfedandwasfueledbyhate‐drivenmusic.NewYorkTimes.RetrievedNovember12,2015,fromhttp://www.nytimes.com/2012/08/07/us/army‐veteran‐identified‐as‐suspect‐in‐wisconsin‐shooting.html6CBSNews.(2013,February6).FloydLeeCorkinspleadsguiltyinFamilyResearchCouncilshooting.RetrievedNovember12,2015,fromhttp://www.cbsnews.com/news/floyd‐lee‐corkins‐pleads‐guilty‐in‐family‐research‐council‐shooting7Yonke,D.(2013,April17).MosquearsonistRandolphLinnsentencedto20years.TheWashingtonPost.RetrievedNovember12,2015,fromhttps://www.washingtonpost.com/national/on‐faith/mosque‐arsonist‐randolph‐linn‐sentenced‐to‐20‐years/2013/04/17/e66b70f2‐a796‐11e2‐9e1c‐bb0fb0c2edd9_story.html8AssociatedPress.(2014,February24).AbdullatifAliAldosaryupdate:Iraqigets5yearsinfederalweaponscase.ABC15Arizona.RetrievedNovember12,2015,fromhttp://www.abc15.com/news/region‐central‐southern‐az/casa‐grande/abdullatif‐ali‐aldosary‐update‐iraqi‐man‐faces‐sentencing‐in‐federal‐weapons‐case9Dorner,C.J.(2013,February13).ChristopherDorner’smanifesto.KTLA5.RetrievedNovember12,2015,fromhttp://ktla.com/2013/02/12/read‐christopher‐dorners‐so‐called‐manifesto10AssociatedPress.(2014,December16).GregoryLynnShraderupdate:Sentencingsetformanconvictedofmailingbomb.ABC15Arizona.RetrievedNovember12,2015,fromhttp://www.abc15.com/news/region‐phoenix‐metro/central‐phoenix/gregory‐lynn‐shrader‐update‐sentencing‐set‐for‐man‐convicted‐of‐mailing‐bomb11BBCNews.(2014,July17).ShannonRichardsongets18‐yearjailtermforpostingricin.RetrievedNovember12,2015,fromhttp://www.bbc.com/news/world‐us‐canada‐2833965312CBSNews.(2013,November4).LAXshooting:PaulCiancia,woundedsuspect,gavepolicecrucialinformation.RetrievedNovember12,2015,fromhttp://www.cbsnews.com/news/lax‐shooting‐paul‐ciancia‐wounded‐suspect‐gave‐police‐crucial‐information13Ahmed,S.,E.Lavandara,andC.E.Shoichet.(2014,April15).AllegedKansasJewishcentergunmanchargedwithmurder.CNN.RetrievedNovember12,2015,fromhttp://www.cnn.com/2014/04/15/us/kansas‐jewish‐center‐shooting14AssociatedPress.(2015,July2).Seattlemanchargedwithmurder,terrorisminNewJersey.TheSeattleTimes.RetrievedNovember12,2015,fromhttp://www.seattletimes.com/seattle‐news/seattle‐man‐charged‐with‐murder‐terrorism‐in‐new‐jersey15WTRF.(2015,February13).Weirtonmanpleadsguiltytoplacingexplosivesaroundcitybuilding.RetrievedNovember12,2015,fromhttp://www.wtrf.com/story/28071877/weirton‐man‐pleads‐guilty‐to‐placing‐explosives‐around‐city‐building16Schenmann,J.(2014,June23).Cop‐killerdeclares,‘Iaminchargenow,’beforefatalshootout.LasVegasSun.RetrievedNovember12,2015,fromhttp://lasvegassun.com/news/2014/jun/23/motive‐cicis‐wal‐mart‐shootings‐remains‐elusive‐sh17Morris,M.(2014,September17).ManischargedwiththeattemptedfirebombingofRep.EmanuelCleaver’sKCoffice.TheKansasCityStar.RetrievedNovember12,2015,fromhttp://www.kansascity.com/news/local/crime/article2143775.html18Lehman,P.andL.M.Schroeder.(2014,November13).EricFreininlettertomomanddadcallsfor'revolution.'TheMorningCall.RetrievedNovember12,2015,fromhttp://www.mcall.com/news/breaking/mc‐eric‐frien‐terrorism‐letter‐charges‐20141113‐story.html19CBSNews.(2014,October24).MotivesoughtinhatchetattackonNYPDofficers.RetrievedNovember12,2015,fromhttp://www.cbsnews.com/news/motive‐sought‐in‐hatchet‐attack‐on‐nypd‐officers20Ohlheiser,A.andE.Izadi.(2014,December1).Police:Austinshooterwasa‘homegrownAmericanextremist.’TheWashingtonPost.RetrievedNovember12,2015,fromhttps://www.washingtonpost.com/news/post‐nation/wp/2014/12/01/police‐austin‐shooter‐belonged‐to‐an‐ultra‐conservative‐christian‐hate‐group21Mueller,B.andA.Baker.(2014,December20).2N.Y.P.D.officerskilledinBrooklynambush;suspectcommitssuicide.TheNewYorkTimes.RetrievedNovember12,2015,fromhttp://www.nytimes.com/2014/12/21/nyregion/two‐police‐officers‐shot‐in‐their‐patrol‐car‐in‐brooklyn.html



22LeMoult,C.(2015,April15).BostonMarathonbombingsurvivorsdealwithalingering,invisibleinjury—tinnitus.PublicRadioInternational.RetrievedNovember12,2015,fromhttp://www.pri.org/stories/2015‐04‐15/boston‐marathon‐bombing‐survivors‐deal‐lingering‐invisible‐injury‐tinnitus23Armstrong,J.(2015,March9).VictimstellcourtofhorrificinjuriesinBostonMarathonbombing.CBSBoston.RetrievedNovember12,2015,fromhttp://boston.cbslocal.com/2015/03/09/more‐gruesome‐testimony‐expected‐in‐boston‐marathon‐bombing‐trial24NewYorkCityDepartmentofHealthandMentalHygiene,(NoDate).Whatweknowaboutthehealtheffectsof9/11:AmessagefromtheCommissioneroftheNewYorkCityDepartmentofHealthandMentalHygiene.RetrievedNovember12,2015,fromhttp://www.nyc.gov/html/doh/wtc/html/know/know.shtml25AssociatedPress.(1973,November10).Murderbulletscyanide‐loaded.SpokaneDailyChronicle.RetrievedNovember12,2015,fromhttps://news.google.com/newspapers?nid=1338&dat=19731110&id=IZJYAAAAIBAJ&sjid=UvgDAAAAIBAJ&pg=7073,3227034&hl26UnitedPressInternational.(1985,July27).PlutoniumfoundinN.Y.'swatersupply:Low‐levelcontaminanttiedtodemandforGoetzcasedismissal.LosAngelesTimes.RetrievedNovember12,2015,fromhttp://articles.latimes.com/1985‐07‐27/news/mn‐6293_1_water‐supply