Fingerprinting Dr. Walker

Background Where do fingerprints come from? Write bold Background Where do fingerprints come from? The friction ridge pattern is determined in the womb (before birth) by the dermal papillae, cells between the surface and lower layers of the skin. The papillae are roughly 2 mm below the surface and form a “negative” of the fingerprint. Cutting into the papillae leaves a scar, but does not change the print.

Background How do fingerprints occur? Write bold Background How do fingerprints occur? Friction ridge skin that deposits oil, perspiration, dirt on object touched Fingerprints are 99% water Cold hands or recently washed hands leave practically NO secretion

Background What makes fingerprints useful? All fingerprints are unique Write all Background What makes fingerprints useful? All fingerprints are unique Fingerprints cannot be changed. Fingerprints display patterns that allow them to be classified.

Can’t be changed? Only instances of changing fingerprints are: injuries or surgery causing deep scarring diseases such as leprosy damaging the formative layers of friction ridge skin Can’t cut deep enough to fully remove skin for fingerprinting

History 1880 – Henry Faulds 1888 – Sir Francis Galton Write bold History 1880 – Henry Faulds Discussed fingerprints as a means of personal identification, and the use of printers ink as a method for obtaining such fingerprints. Credited with the first fingerprint identification of a greasy fingerprint left on an alcohol bottle. 1888 – Sir Francis Galton  Published his book, "Fingerprints", establishing the individuality and permanence of fingerprints. His book included the first classification system for fingerprints.

History 1896 - Sir Edward Richard Henry 1918 – Edmund Locard Write bold History 1896 - Sir Edward Richard Henry Developed the print classification system that would later be used in Europe and North America. 1918 – Edmund Locard 12 point match Locard wrote that if 12 points were the same between two fingerprints, it would suffice as a positive identification.  This is the most common standard for print matches today

Databases IAFIS UIAI – India FBI’s database Write bold Databases IAFIS FBI’s database 60 million prints contained (to date) Collected since 1924, automated since 1974 UIAI – India Current database, known as AADHAAR, has over 200 million prints Hopes to have 600 million by 2014

Who Gets Fingerprinted? Write all Who Gets Fingerprinted? Criminals fingerprints Federal job applicantsemployees Military Aliens (aka non-residents) Anyone else who wants them on record

Features of Fingerprints From left: Arch Loop Whorl – circular pattern within print These are the basic features

Features of Fingerprints Tented Arch Distinct angles within arch Twinned Loop Distinct loops going in two separate directions Central Pocket Loop Whorl within a loop

Features of Fingerprints Lateral pocket loop Distinct loops in two different directions Composite Multiple distinct features Accidental Multiple features, pattern within patterns

Types of Fingerprint Evidence Write all Types of Fingerprint Evidence Latent Small amounts of grease, sweat, and dirt on surface of skin Patent (aka contaminated) Dirty finger (dust, blood, ink, oil) Plastic Left in paint, wax, chocolate, dust, etc. Leaves a NEGATIVE impression of friction ridge

Fingerprinting Reagents Write all Fingerprinting Reagents Reagent Reacts With Used On? Resulting Color Iodine Porous or non-porous Ninhydrin Porous Silver Nitrate Cyanoacrylate Non-porous

Fingerprinting Reagents Write all Fingerprinting Reagents Reagent Reacts With Used On? Resulting Color Iodine Adheres to sebaceous (fatty) material Porous or non-porous Yellow to Brown Ninhydrin Reacts with amino acids Porous Ninhydrin (purple) Silver Nitrate Reacts with salts Brown or black Cyanoacrylate Polymerizes materials in print – used for preservation Non-porous White (can be enhanced)

Fingerprinting Reagents Write all Fingerprinting Reagents Reagent Reacts With Used On? Resulting Color Regular Powder Non-porous and porous. Depends on exact powder and surface Amido black Bloodstained specimens. Blue - black Luminol Chemical reaction with hematin. Presumptive test for blood. Titanium Dioxide Use on plastic, electrical & duct tape

Fingerprinting Reagents Write all Fingerprinting Reagents Reagent Reacts With Used On? Resulting Color Regular Powder Adheres to moisture and lipid components. Non-porous and porous. Depends on exact powder and surface Amido black Chemical reaction with protein in blood. Bloodstained specimens. Blue - black Luminol with hematin. Presumptive test for blood. Luminescence (view with fluorescent light) Titanium Dioxide Use on plastic, electrical & duct tape White

Collection Procedure Photograph all prints prior to collection!! Write all Collection Procedure Photograph all prints prior to collection!! Use cellophane tape over prints Prevent air pockets Smooth gently over print with finger. Slowly remove from surface Apply tape to fingerprint backing card that has been filled out BEFOREHAND. Use appropriate color of backing card

Sources http://onin.com/fp/fphistory.html http://ridgesandfurrows.homestead.com/index.html https://www.fbi.gov/services/records-management/foipa/privacy-impact-assessments/iafis