Fundamentals of Crime Mapping

Chapter 1

Instructor name here

General class instructions here

Class basics and introductions

ArcGIS◦ “GIS Tutorial”

ESRI (www.esri.com) 180 day copy of ArcGIS

Alternative: “Getting to Know ArcGIS for Version 9” http://

gis.esri.com/esripress/display/index.cfm?fuseaction=display&websiteID=144&moduleID=0

◦ Get 60 day Evaluation copy from ESRI Website (order early)

◦ http://www.esri.com/software/arcgis/arcview/eval/evaluate.html

◦ Get 1 year Student license from ESRI for $100.00

◦ http://www.esri.com/industries/university/education/sitelic.html#individual

Additional ArcGIS Software

CrimeStat III ◦ http://www.icpsr.umich.edu/CRIMESTAT/◦ Manual is also very good reference manual for

spatial statistics

Additional CrimeStat III Software

The more you desire to learn, the more you learn

Practice, practice, practice

Develop a thick skin◦ Your first maps are going to be awful, listen to constructive criticism and don’t

take it too personally

Don’t give away this new skill◦ Practice and keep up to date with it◦ Will reward you in many professions as an additional skill

that is marketable

More class introduction

Introduction to Crime Mapping

Victims Suspects Environment Time

◦ Who, What, When, Where, Why and How?

Criminal Event

The study of crime and criminal behavior◦ No generally accepted single theory that explains

the existence of crime in a society◦ Consensus perspectives

Approach crime as a normal and healthy part of any society

◦ Conflict perspectives Argue that crime is the result of group conflict and

unequal distributions of power

Criminology

Macro◦ Make assumptions about societal-level variables,

including the structure of government and the economy and how these variables impact crime rates within a society

Micro◦ Make assumptions about individual characteristics

(IQ, mental state, temperament, biological characteristics, and personal finances, for example) and how they influence a person’s decision to commit a crime

Levels of application

Time and Place AsAspects of Criminal Event

TimeSuspect

Environment/Place

Victim

Economic composition of a community contributes to crime by affecting neighborhood order

Higher juvenile delinquency rates tended to cluster in certain neighborhoods within urban areas

Poverty and residential instability,◦ Impacted both the physical appearance and the social structure of

the neighborhood itself High population density High population mobility Higher numbers of suitable targets Motivated offenders coexisted with little or no guardianship Produces higher rates of crime Higher rates of crime regardless of who lived there The area, not the people, is criminogenic

Social Disorganization Theory

Three very basic premises◦ Environmental Criminology

Environment can affect crime Target rich environments

◦ Routine Activity Theory We all have routines, in our down time, we commit crime Mental maps and nodes, paths, awareness space

◦ Rational Choice Theory Suspects plan to some degree their crimes If we understand the reason for the choices, we can

understand and forecast where the offender goes next Crime Pattern Theory is a combination of all of

these

Criminology

Two Good Web References◦ http://www.geo.hunter.cuny.edu/capse/projects/nij/crime_

bib1.html◦ http://en.wikipedia.org/wiki/Crime_mapping

References

Certain locations can be crime attractors (Crime pattern theory)◦ Bank ATM◦ Sports Venues (Coyotes Stadium, etc)

More potential victims Security

◦ Design of building or path through makes cover and concealment available to suspect and disadvantage to victim

Ease of escape◦ Ability to commit crime and leave the scene without

detection◦ Darkness◦ Closeness of a freeway, etc.

Crime Prevention through Environmental Design (CPTED)

Motivated offender Suitable target Absence of a capable guardian

Routine Activities Theory

Mental Maps◦ If you had to draw your world right now, what would it

look like?◦ Where do you live, work, play? (nodes)◦ How do you get back and forth between these places?

(Paths)◦ The areas between nodes and paths that are known to

you because of your routine activities, are your “awareness spaces”

◦ I drive to work everyday and see construction and say, “Wow, it sure is growing out this way”

The person with a criminal intent says, “Wow, look at all the construction equipment that isn’t locked up around here!”

◦ Can be a great interview technique, because all maps are “true!”

Mental Maps

Routine Activities Theory Analysis Triangle

Family,Probation Officer

Home Owners,Teachers

Police,Private Security

Relation to Crime Mapping

Nodes Paths Awareness Space Escape Routes Geography of

Victimology

• What does this offender’s nodes maybe tell you about him/her?

Journey to Crime Result

Intelligence Application

Theory should power all mapping and analysis projects◦ Think about

Suspect’s search patterns Least effort Mixed scanning

Find an area then find a target Bank ATM, Sports Arena, Big Event, Mall

Awareness spaces Knowledge ComfortRoutines and rhythms Obligatory time (work etc.) Discretionary time (Crimes occur now)

Considerations

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Marauder Vs. Commuter

Focus on Crime Theory:

Marauder orPoacher

CommuterOr Hunter

We are all human beings and each of us uses some thought process to make decisions

Criminals and “normal” people are fundamentally the same

We make decisions on where to commit our crime through:◦ What is the benefit I receive?◦ Is it relatively safe?◦ Can I escape easily?◦ Number of potential witnesses to my crime?

Identification of myself by police and others

Rational Choice Theory

Hypothesis testing

should be an

everyday part of crime

analysis

Crime analysis◦ Focus on events

Administrative Operational or Police Operations Analysis

Strategic Tactical

Criminal intelligence analysis◦ Focus on people◦ Organized criminal activity and seeks to link people, events, and

property Investigative analysis

◦ Focus on investigation of specific crimes◦ Victim characteristics and elements of crime scenes are studied

to discover patterns that link related crimes together◦ Investigative support

Categories of Crime Analysis

“is the systematic study of crime and disorder problems as well as other police-related issues—including sociodemographic, spatial, and temporal factors—to assist the police in criminal apprehension, crime and disorder reduction, crime prevention, and evaluation” (Boba, 2005, p. 6)

“focused on the study of criminal incidents; the identification of patterns, trends, and problems; and the dissemination of information that helps a police agency develop tactics and strategies to solve patterns, trends, and problems” (Bruce, 2004, p. 15)

Definitions of Analysis

Common Crime Analysis Goals

Provide information that is fast, reliable and accurate (data quality)

Improve administrative reports where needed

Improve strategic analysis efforts for better decision making

Begin proactive analysis of several crime types that can be impacted by crime analysis efforts

Involves the presentation of key findings of crime research and analysis to audiences within law enforcement, local government, and citizenry based on legal, political, and practical concerns including:◦ A report on demographic changes in the jurisdiction◦ Miscellaneous crime statistics to support grant

applications◦ Preparation of Uniform Crime Report (UCR) or

Incident-Based Reporting System◦ Hotspot, pin, or reference maps for the jurisdiction

Administrative Analysis

Administrative Analysis Objectives

Assist in general reporting Improve UCR coding processes by

reviewing coded reports for accuracy Suggest improvements to the

management system when needed Produce reports and data in a timely

manner Provide general hot spot and crime

distribution maps and reports on an ad-hoc basis

Do staffing studies

Administrative (bean counting)◦ Reference maps◦ Hot spot or hot area maps◦ Graduated symbol maps◦ Pin maps

Larger geography area Longer time periods Less specific focus Multi-layer geoprocessing (thematic

mapping)◦ Using several layers of data to make one final map◦ Redistricting is an example

Administrative Maps

Involves the study of crime and other law enforcement issues to identify long-standing patterns of crime and other problems and to assess police responses to these problems (Boba, 2005)

Typically, this analysis involves collecting a great deal of information about criminal events. In addition, “helping agencies to identify root causes of crime problems and develop creative problem-solving strategies to reduce crime” is a key goal in strategic crime analysis (IACA)

Strategic Analysis

Strategic Analysis Objectives

Create hot spot maps by various geographic areas and boundaries◦ Do time comparison studies

Create reports that are easily read and explain general date, time, and day of week distributions of crime in specific geographic areas identified in the administrative process

Find “thresholds” of activity in specific geographic areas to provide weekly or monthly strategic battle plans to all units of the department

Create new reports and processes needed to support this function throughout the department

Database support

Strategic◦ Hotspot maps◦ Graduated symbol maps◦ Pin maps (limited)◦ Multi-layer, thematic, geoprocessing

Recurring or significant problem you are trying to find or isolate

Smaller geographic area Shorter time period More specific focus Problem-solving or intelligence-led policing

workhorse

Strategic Maps

Examines recent criminal events and potential criminal activity by analyzing how, when, and where the events occur to establish patterns and series, identify leads or suspects, and to clear cases (Boba, 2005)

Tactical Analysis

Tactical Analysis Objectives

Find trends, clusters, patterns, sprees and series of criminal activity through proactive review of reports.◦ Identify the next day of week, time of day, and

likely date of a new crime by the same offender (s) (Statistical Analysis)

◦ Provide additional investigative data from police files and resources on similar crimes or M.O. (Database Searches)

◦ Identify the likely location of a new crime in a series or trend (like, ellipses, rectangles, probability grid analysis)

◦ Identify the likely home address location or anchor point for an offender and provide person information to investigative units for consideration (journey to crime)

◦ Repeat as needed

Tactical◦ Hot spot maps◦ Graduated point maps◦ Pin Maps◦ Thematic mapping

Waiting for the next incident to happen Predictions for new hit Journey to crime analysis

◦ Very specific focus◦ Short time spans analyzed◦ Very limited to some range of geography

Tactical maps

Benefits of Crime Analysis

More data is available to you◦ Become “intimate” with the data

Data problems can be identified and corrected

Excellent tool for goal planning and completion and applying the SARA model to problems:◦Collect, collate, analyze, disseminate, and

EVALUATE vs. S.A.R.A.

Geographic Information Systems have developed over the past 30 years

◦ First crime map in early 1900’s in New York◦ First computerized crime map in 1960’s

Canada led the way◦ More common use in late 1980’s, early 90’s

GIS use has increased dramatically in the past 5-10 years, however may still be underused in some police departments

2002 ACJC study, only 15% of AZ agencies using it

ACJC Crime Mapping in Arizona 2002.pdf

GIS in history

The “SYSTEM” part of GIS could be used to describe all of the diverse assortment of data that a normal police department collects during day to day operations

◦ Geographic data (incident locations, home addresses, etc)◦ Data that can be tied to the geographic data (person’s DOB,

Vehicle make, property, M.O., etc.) A GIS can assist police with

◦ optimizing limited resources◦ directing enforcement activities to needed areas◦ streamlining and improving business processes◦ identifying critical information problems within datasets

collected and maintained.◦ Quality control

With this increase in the amount of data available to decision makers, we have to be able to make sense of all of this data.

GIS defined

In the business community this is often described as “business intelligence” or the process of taking the bits and pieces of data we collect everyday,

Ordering it and organizing it so that it makes sense and provides information, to assist other analysts, administrators, detectives, and patrol officers

To develop knowledge to prevent crimes, catch criminals, or enhance public safety.

Business Intelligence

My audience determines what type of map I produce and that you will have many different people and purposes within the audiences you will address as a crime analyst

Key element

Has increased (or can increase) efficiency in the data collection processes

◦ Easy to do, so more data is used◦ When you are mapping data, you often find the “big”

accuracy or reliability problems with your data collection systems and can make recommendations to improve them

◦ Quality assurance measures can be identified Promotes by it’s sheer nature – DATA SHARING

◦ GIS the common language

GIS Rewards

Saves time for your agency when used correctly

Saves money by understanding the processes or the work flow of the data you will use

GIS Rewards

You will learn more information about crime in your jurisdiction faster and become the resident “expert” in data, software, and often hardware

GIS Rewards (not always a good thing)

You will develop new partnerships with people◦ Your own city (IT staff, Engineering, Utilities, Planning,

etc.)◦ In our county (IT Staff, GIS section, Elections,

Association of Governments, etc.)◦ Between other law enforcement agencies

Data sharing projects and cooperative grant processes◦ In your state and with the federal government

Homeland security Grants Geospatial One-stop web sites

GIS Rewards

With GIS, we deal with several different types of data. In the ArcMap application we deal mostly with 4 basic data formats:◦ Vector

Points Lines (sometimes called Arcs) Polygons

◦ Raster Image

The Software for GIS

Points◦ incidents or events

Radio calls Crimes

◦ physical features Police stations Schools Evidence found

The GIS Software

Lines (sometimes called Arcs)◦ Streets◦ Knows start and end◦ Can be used for routing◦ Distances between things (length)◦ Knows what’s on the right or left◦ Boundary lines

GIS Software

Polygons◦ Are bounded by limits of box◦ Knows what is within and what borders itself◦ Aggregation container◦ Knows it’s AREA

GIS Software

Raster vs. Vector data◦ Points, lines and polygons are Vector data with

aggregation or not Discrete data (a line stitched on to a blanket)

◦ Raster data is like a weather map Satellite photos, radar, aerial images Continuous data (the entire blanket)

GIS Software

Raster or Vector?

Raster or Vector?

Raster or Vector?

“A computerized mapping system that allows a police department to analyze geographic and related data collected during the course of police activities, to provide insight into better crime fighting strategies, community based policing program evaluation, administrative, strategic, and tactical planning and intervention activities, predicting suspect behavior and patterns in active investigations, and to utilize the data more effectively through graphic display of data in a easy to understand “map” format, as well as develop strategies to guarantee accurate data collection to achieve sound analysis products for decision making processes, across all units within a police department.”

One Law Enforcement GIS Definition

IACA Vendor List◦ http://www.iaca.net/Software.asp

Crime Mapping (NIJ Maps)◦ http://www.ojp.usdoj.gov/nij/maps/software.html

IACA (International Association of Crime Analysts)◦ www.IACA.net

AACA (Arizona Association of Crime Analysts)◦ http://www.aacaonline.org/

And many many more listed in the textbook

Resources

Projections

The method used to transfer locations on the Earth’s surface to a flat map is called projection.

Projections…3D to 2D

There are hundreds of mathematical calculations to make the data at some point on the earth’s surface the “most” accurate.

The earth is not perfectly round (spheroid)◦ Hills and valleys, etc

All map projections distort the surface in some fashion◦ Area ◦ Shape ◦ Direction ◦ Bearing ◦ Distance ◦ Scale

Projections…3D to 2D

Common Projection for USA is Universal Transverse Mercator◦ Latitude and Longitude lines◦ State plane coordinate system derived from this

projection for better accuracy Nad 1983, Fips 0202 Az Central – Maricopa and other counties

Most states have 3 zones (FIPS zones) International feet

Measurement units

Projections…3D to 2D

Important to know projection to share data Important to measure correctly ArcGIS Shapefile creates a .PRJ file which

stores the projection information so it can be used with other data

I sharing data:◦ Provide complete projection

State Plane Coordinate System, Nad 1983, Fips 0202, Az Central, Intl Feet (or meters, feet, etc)

Projections…3D to 2D

ArcGIS –ArcView ArcMap Level

Table of Contents

Toolbars and Menus

Menu Bar or Menu Items

Map DisplayMap WorkspaceStart-up

Dialog

ToolBox

GIS Software with 3 levels◦ ArcInfo◦ Arc Editor◦ ArcMap (what we have)

Made by ESRI◦ www.esri.com

Initial steep learning curve Can do just about anything and only

limited by your imagination

The ArcGIS Project

The ArcGIS Project

Map Display

Menu Bar (Activate by clicking and

choosing item)

TOC Tabs (Display, Data Source, and Selected records

views)

Table of Contents

The ArcGIS Project

Map Display

Checked, or Turned On or Visible in Map

Display

Display tab – shows you what layers are available in the data

frame and can be viewed on the map display area

Table of Contents

Highlighted or “Selected”

The ArcGIS Project

Map Display

File Directory Path

Source – gives you the file location for the data in the

project

Table of Contents

The ArcGIS Project

Map Display

Selectable and records selected

Selection – let’s you choose which themes can have records

selected, and which themes have records selected in them -bolded

and number of records in “()”

Table of Contents

Not Selectable

The ArcGIS Project

Map Display

Themes or layers

Data Frame Standard

toolbar

Layout toolbar

View ToolsTable of Contents

The ArcGIS Project

Map Display

Right Click on Data frame to get data

frame properties menu

Table of Contents

The ArcGIS Project

Map Display

Right click on theme name to get Layer Properties menu

Table of Contents

The ArcGIS Project

Map Display

Symbology Tab Allows us to make

changes to how the data is displayed

and classified

The ArcGIS Project

Definition query tab allows us to choose what data we see

The ArcGIS Project

Label tab let’s us label just about anything on the map automatically

and we have more choices and options than we can shake a

stick at

The ArcGIS Project

Map display View

layout View

Standard tools active – Layout tools not active

Layout tools active – Standard tools also active

You need to make sure you keep the layout tools and the

standard tools separate in your mind as they work on

the data differently

The ArcGIS Project

Map Display

Arc Toolbox

Add Data

Table of Contents

The ArcGIS Project

Allows us to add data from a variety of sources:• GIS Layers• Tables• Images• ODBC and OLE DB Connections to databases

The ArcGIS Project

Map DisplayTable of Contents

Arc Toolbox

The ArcGIS Project

Map Display

Arc Catalog Button

Table of Contents

The ArcGIS Project

New program opens – File Information, data Structure

and metadataLibrary of sorts

You can manage your data, search and find data, view data, and add metadata (data about data) in Arc

Catalog. You can also create new data and drag and drop data into ArcGIS from Arc

Catalog

Querying Tables in ArcMap

Be sure to use complete SQL structure:◦ [FieldName] = ‘Something’◦ Field, operator, and Value

Querying Data in ArcCatalogue

Useful for finding data

that meet your

geographic boundaries or contain

some element

you need

Practice Makes Useful Use the exercises in class and practice,

practice, practice!

Practice Makes Perfect You WILL find the light at the end of the

tunnel

Definitions and Terms

Crime Types Trend – A crime trend is the occurrence of similar

offenses in a geographic area that have increased or decreased within a given time period and this can be measured.

Pattern – A crime pattern is the occurrence of similar offenses in a geographic area that may or may not be committed by the same suspect or suspects.

Cluster – A crime cluster is the occurrence of similar offenses within close proximity to each other potentially leading to identification of a crime series or not.

Series – A crime series is the occurrence of offenses showing evidence that the same suspect or suspects has committed the crimes. This is verified through similar MO’s or suspect descriptions.

Spree – A crime spree is a set of crimes committed sequentially by the same suspect or suspects over a short period time.

Definitions and Terms

General Terms Hot Spot – An area that has been identified to have

more crime than another area or has a higher “density” of crimes.

Density – Density is a term applied to geographic elements and their relationship to each other. A location or group of crimes is considered more dense as their numbers increase and the proximity to another location or crime is reduced.

Threshold Analysis – A product used as an early warning system for crimes in a specific geographic area to determine if the total numbers are higher or lower than the a previous, equal, time period.

Spatial Analysis (Geoprocessing) – The science of using geographic elements and their relationship to other geographic elements to analyze crime and crime associations.

GIS – Geographic Information Systems. Also known as computer mapping.

Definitions and Terms

General Terms Frequency Distribution – A listing of numbers or scores

in ascending or descending order. Mean – The mathematical average of a set of numbers. Median – The middle score in a distribution. Mode – The most frequent score in a distribution. Standard Deviation – This is the average of the

differences between scores in a frequency distribution yielding to a normal distribution (bell-shaped curve).

Central Tendency – A term used to describe the proximity of a score in a distribution to the mean of the same distribution.