criminal investigations part two

Copyright 2005 - 2009:Hi Tech Criminal Justice, Raymond E. Foster

Law EnforcementLaw EnforcementCriminal InvestigationsCriminal Investigations

Part IIPart II


DNA BasicsDNA Basics

Transfer theory demonstrates that Transfer theory demonstrates that wherever we are – we leave behind wherever we are – we leave behind evidence we where there!evidence we where there!

Perhaps our fingerprints; or, Perhaps our fingerprints; or, Our bodies are constantly shedding Our bodies are constantly shedding

cells, releasing vapor containing cells cells, releasing vapor containing cells and shedding hair – we leave it and shedding hair – we leave it everywhereeverywhere


DNA BasicsDNA Basics(smaller and smaller)(smaller and smaller)

Our bodies contain 100 trillion cells.Our bodies contain 100 trillion cells. Most cells contain a center piece Most cells contain a center piece

called a nucleus.called a nucleus. The nuclei of our cells contain 23 The nuclei of our cells contain 23

pairs of chromosomes which are the pairs of chromosomes which are the biological instructions of who we arebiological instructions of who we are

During conception our parents During conception our parents contribute one half of each pair.contribute one half of each pair.



Inside each chromosome there are as Inside each chromosome there are as many as a hundred thousand pair of many as a hundred thousand pair of genes – the fundamental building genes – the fundamental building blocks of our hereditary traits.blocks of our hereditary traits.

There are many variations for genes, There are many variations for genes, but really two classifications.but really two classifications. General – those that identify us as General – those that identify us as

humanshumans Specific – those that give us individual Specific – those that give us individual

characteristicscharacteristics



Our genes are made up of Our genes are made up of Deoxyribonucleic Acid (DNA)Deoxyribonucleic Acid (DNA)

DNA consists of a long string of four DNA consists of a long string of four repeating nucleotides:repeating nucleotides: Adenine (A)Adenine (A) Cytosine (C)Cytosine (C) Guanine (G)Guanine (G) Thymine (T)Thymine (T)

This long This long string of string of repeating repeating nucleotides is nucleotides is called a called a polymerpolymer



CellsCells

NucleusNucleus

ChromosomeChromosomess GenesGenes

DNADNA



The order of the four nucleotides (A, C, The order of the four nucleotides (A, C, G, T) within the polymer determine the G, T) within the polymer determine the information contained therein.information contained therein. Different order – different informationDifferent order – different information



A complete DNA A complete DNA molecule has to molecule has to polymer strands polymer strands with four bases – it with four bases – it is a tightly woven, is a tightly woven, double helix, with double helix, with 3.3 billion pairs of 3.3 billion pairs of nucleotidesnucleotides

Base PairsBase Pairs



DNA, like digital information has DNA, like digital information has beginning codes and ending codes – beginning codes and ending codes – to tell us where “packets of genetic to tell us where “packets of genetic data” or segments begin and end.data” or segments begin and end.

With DNA, at the end and beginning With DNA, at the end and beginning of DNA stands are A/T and G/Cof DNA stands are A/T and G/C



Most of our DNA is exactly the same, Most of our DNA is exactly the same, only a small percentage is different only a small percentage is different from each other.from each other.

The location where specific DNA The location where specific DNA information is located is called a information is located is called a locus.locus.

The information that is different The information that is different between individuals is called between individuals is called Polymorphisms – the part examined Polymorphisms – the part examined during forensic DNA analysis.during forensic DNA analysis.



DNA analysis can compare:DNA analysis can compare: short repeating patterns and look short repeating patterns and look

at the variation in length – called at the variation in length – called Variable Number of Tandem Variable Number of Tandem Repeats (VTNR) Repeats (VTNR)

base pairs – called Polymerase base pairs – called Polymerase Chain Reaction (PCR) within Chain Reaction (PCR) within Polymorphisms (specific genes)Polymorphisms (specific genes)



Recall general and specific genes:Recall general and specific genes: General genes (DNA) are called General genes (DNA) are called

MonomorphismsMonomorphisms Specific genes (DNA) are called Specific genes (DNA) are called

PolymorphismsPolymorphisms

DNA Analysis is conducted DNA Analysis is conducted on Polymorphismson Polymorphisms


DNA DatabasesDNA Databases

Like fingerprint information, DNA Like fingerprint information, DNA information is converted to a numerical information is converted to a numerical value for ease of search.value for ease of search.

Combined DNA Information System Combined DNA Information System (CODIS) is actually a combination of (CODIS) is actually a combination of databases.databases. 153 Laboratories in 49 states153 Laboratories in 49 states Actually includes three different type of Actually includes three different type of

databasesdatabases Convicted Sex Offender, other offenders, missing Convicted Sex Offender, other offenders, missing

personspersons


DNA DatabasesDNA Databases

Database ConcernsDatabase Concerns Who is included? Convicted, arrested or Who is included? Convicted, arrested or

suspected? It varies from state to state.suspected? It varies from state to state. What about juveniles? While juvenile What about juveniles? While juvenile

arrest records don’t necessarily follow a arrest records don’t necessarily follow a juvenile into adulthood, the DNA database juvenile into adulthood, the DNA database does?does?

Since a portion of DNA information is Since a portion of DNA information is familial – if your sibling or parent is in the familial – if your sibling or parent is in the database – so is a part of you.database – so is a part of you.

What about research?What about research?


SoftwareSoftware Investigative workload Investigative workload

Case assignmentCase assignment Clue managementClue management Witness managementWitness management Case coordinationCase coordination ProductivityProductivity

Screen Capture provided by Crimestar Screen Capture provided by Crimestar CorporationCorporation


SoftwareSoftwareCrime Scene DrawingsCrime Scene Drawings

Crime sceneCrime scene drawings are drawings areoften used as a means ofoften used as a means ofdocumenting the locationdocumenting the locationof evidence, assisting inof evidence, assisting indetermining the sequencedetermining the sequenceof events and explaining aof events and explaining acrime to a jury. Software,crime to a jury. Software,some very similar to draftingsome very similar to draftingsoftware aids in thesoftware aids in theproduction of two dimensionproduction of two dimensioncrime scenecrime scene representations. representations.

Photograph provided by Robert Eplett, California Photograph provided by Robert Eplett, California Governor’s Office of Emergency ServicesGovernor’s Office of Emergency Services


SoftwareSoftwareLink AnalysisLink Analysis

Link analysis Link analysis software can often software can often help in organizing help in organizing the vast amount of the vast amount of information and information and evidence a complex evidence a complex case can producecase can produce

Screen Capture provided by Pen-Screen Capture provided by Pen-Link™Link™


Digital PhotographyDigital Photography

Digital photography is a picture stored in Digital photography is a picture stored in the language a computer can understand. the language a computer can understand. It takes that information and converts it It takes that information and converts it into a visual display.into a visual display. It has numerous benefits like storage and It has numerous benefits like storage and

analysis.analysis. Because it is easier to manipulate a digital Because it is easier to manipulate a digital

image than a traditional photograph, additional image than a traditional photograph, additional software security, procedures and protocols software security, procedures and protocols are necessary to maintain the chain of custodyare necessary to maintain the chain of custody


High Definition SurveyHigh Definition Survey

Using laser technology a Using laser technology a three dimensional three dimensional representation of a crime representation of a crime scene is created.scene is created.

New New InformationInformation

Hyperlink to more Information

Photograph provided by lecia-Photograph provided by lecia-geosystemsgeosystems


High Definition SurveyHigh Definition SurveyNew New InformationInformation

Investigators, Investigators, prosecutors and juries prosecutors and juries can now return to the can now return to the scene of the crime in a scene of the crime in a virtual world.virtual world.

ReconstructionReconstruction

TrialsTrials

TrainingTrainingA three dimensional representation of A three dimensional representation of a seated man with a guna seated man with a gun

Photograph provided by lecia-geosystemsPhotograph provided by lecia-geosystems


Law EnforcementLaw EnforcementCriminal Criminal InvestigationsInvestigations Part Two Part Two

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criminal investigations part two

Education

dna basics dna analysis

dna basics smaller

specific dna information

deoxyribonucleic acid

dna stands

portion of dna information

general genes dna

polymorphisms dna analysis