The Enforcement The Enforcement FunctionFunction

Week FiveWeek Five

Transfer TheoryTransfer Theory

Edmund Locard, a Edmund Locard, a French Scientist French Scientist developed the developed the theory that contact theory that contact between between individuals or individuals or objects results in a objects results in a transfer of material transfer of material between them. between them.

Trace EvidenceTrace Evidence HairHair FiberFiber GlassGlass PaintPaint DustDust DirtDirt ChemicalsChemicals FirearmsFirearms

FluidsFluids BloodBlood Bite MarksBite Marks Shoe PrintsShoe Prints Tool MarksTool Marks WoundsWounds DocumentsDocuments FingerprintsFingerprints

The First Major Systems of The First Major Systems of Personal IdentificationPersonal Identification

Anthropometery Anthropometery exact measurements of an individuals body exact measurements of an individuals body

yields a characteristic formula for yields a characteristic formula for comparison.comparison.

Dactlography Dactlography FingerprintsFingerprints

Alphonse Bertillon and Dactylography

The West Brothers case is attributed to the ascendancy of fingerprints over other means of personal identification

A 1924 Act of Congress established the FBI Identification Division

By 1946 they had 100 Million Fingerprint cards

Henry Classification SystemHenry Classification System

AutomaticFingerprintIdentificationSystem

Lifting PrintsLifting Prints• Plastic – Found in a soft surface like Plastic – Found in a soft surface like

wax, paint or putty.wax, paint or putty.• Visible – Contact with a wet fluid like Visible – Contact with a wet fluid like

blood.blood.• Latent – Meaning “Hidden” These Latent – Meaning “Hidden” These

prints are left by the oils secreted by prints are left by the oils secreted by our hands and are generally not our hands and are generally not visible.visible.

Dusting for PrintsDusting for PrintsPowders have differentPowders have differentproperties, for instance color.properties, for instance color.Common colors are black,Common colors are black,white, gray, aluminum, red,white, gray, aluminum, red,and gold. Color is selected toand gold. Color is selected tomake the best contrastmake the best contrastbetween the print and thebetween the print and thesurface. For instance , a surface. For instance , a

whitewhitepowder might works best onpowder might works best ona dark surface.a dark surface.

FumingFumingThere are several types ofThere are several types offuming, the most recent fuming, the most recent

isis““super glue fuming.” super glue fuming.”

SuperSuperglue contains the glue contains the

chemicalchemicalCyanoacrylate. WhenCyanoacrylate. Whenheated this substanceheated this substancesticks to trace oils, sticks to trace oils,

hardenshardensand when dry it is visible.and when dry it is visible.

Firearms Identification

BallisticsBallistics Class Characteristics are identified Class Characteristics are identified

by by lands.lands.

Individual Characteristics are Individual Characteristics are identified by identified by striationsstriations

National Integrated Ballistic National Integrated Ballistic Identification System Identification System

In 1993, prior to NIBIN’s, the FBI (DRUGFIRE)In 1993, prior to NIBIN’s, the FBI (DRUGFIRE)and ATF (BULLETPROOF/CEASEFIRE)and ATF (BULLETPROOF/CEASEFIRE)established separate computerized ballisticsestablished separate computerized ballisticsimaging systems. NIBIN was established in 1997imaging systems. NIBIN was established in 1997to unify these systems. There are currently to unify these systems. There are currently

overover220 crime labs participating.220 crime labs participating.

Deoxyribonucleic Acid Deoxyribonucleic Acid Knowledge of the Knowledge of the

structure of DNA began structure of DNA began with the discovery of with the discovery of nucleic acids in 1869. nucleic acids in 1869. That genes control the That genes control the synthesis of enzymes synthesis of enzymes was understood in the was understood in the 1940s. In 1953, an 1940s. In 1953, an accurate model of the accurate model of the DNA molecule was DNA molecule was presented, thanks to presented, thanks to the work of Rosalind the work of Rosalind Franklin, James Watson, Franklin, James Watson, and Francis Crick and Francis Crick

Historical Evolution of Criminal Historical Evolution of Criminal InvestigationsInvestigations