Fingerprints A Brief History Chinese: 3000 yrs. Ago, Chinese used fingerprints to sign legal documents Henry Fauld (1890): Suggested finger ridges could be used to identify criminals. William Herschel (1870): English civil servant in India; required natives of India to sign contracts with the imprint of their right hand. Alphonse Bertillon: Anthropometry-no two people have the same 11 measurements. Used 11 body measurements to identify individuals. Included height reach, width of hand, length of left foot, etc… Francis Galton: Published the book “Fingerprints.” Described 3 main fingerprint patterns; arches, loops, and whorls. United States: Henry System (1899)-Developed a fingerprinting system used by the FBI to date. First used by the NYC Civil Service Commission. FBI currently has the largest collection of fingerprints in the world. United States vs.Byron C. Mitchell (1999): A defendant’s attorney argued that fingerprints could not be proven unique. Judge upheld, said fingerprints were unique and could be admissible in court.

Human skin is the first line of defense. 2 layers--epidermal and dermal Papillae- Boundary between the 2 layers, that contain the ridge patterns. Sweat glands secrete oil that leaves an identification residue conforming the ridge pattern. sweat pores Sweat gland Epidermal Papillae Dermis Fingerprint Anatomy

Fundamental Principles of Fingerprints 1-A fingerprint is an individual characteristic; no two fingers have yet to possess identical ridge characteristics. Individuality of a fingerprint is not determined by the general shape, but by the examination of ridge characteristics (minutiae) Type, number, and location of ridge characteristics -Fingerprints have 150 different characteristics. -match 8-16 for an identification.

Fundamental Principles of Fingerprints 2- A fingerprint will remain unchanged during an individual’s lifetime. -Fingerprints form in the 17 th week of gestation -Twins do not have matching fingerprints. -If a person tries to change the print: mm below the surface 2- Leaving scars

Fundamental Principles of Fingerprints 3- Fingerprints have general ridge patterns that permit them to be systematically classified. - All prints can be classified as a loop, whorl, or arch -Print: Core (center), Deltas-form triangles on the side of the print 65% of all fingerprints in the world are loops.

Fundamental Principles of Fingerprinting Cont. Loop A loop must have one or more ridge lines entering from one side of the print, recurving, and exiting from the same side.

Fundamental Principles of Fingerprinting Cont. 30% of the population have whorls Must have two deltas Resembles a Bull’s eye or target

Fundamental Principles of Fingerprinting Cont. Arch 5% of the population have arches The ridge lines enter from one side of the print and exit from the opposite side.

Fingerprint Classification Several steps Used as the first step in a crime scene Must identify the presence of a whorl Assign a numerical value based on the finger it (whorl) was found on Used to search databases Example: Right index and right middle fingers are whorls and all the others are loops.

Automated Fingerprint Identification Systems AFIS Uses automatic scanning devices that convert the image of a fingerprint into digital image characteristics that contain data showing ridges at their points of termination or splits in the ridge. 40,000 new prints everyday Identifies 8,000 fugitives a month Looks at 67 years in 20 mins.

Methods of Detecting Fingerprints Visible Prints Occur when a finger has been placed in a colored substance like blood, paint, ink, mud, etc. Plastic Prints Prints that are made in soft substances like wax, soap, plastic 3D model of print Non-Porous Surfaces Hard, smooth, nonabsorbent, glass, mirror, painted wall Latent Prints “lie hidden” Prints appear invisible, can be developed to be seen. Porous Surfaces Soft, absorbent materials Cloth, ceramic, concrete

Common Techniques Used 1. Dusting with Carbon Powder on white or light colored surfaces. Color contrast Dust gets stuck in oil of print Use tape to lift print 2. Dusting with Lanconide Powder for black surfaces. White powder Gives color contrast 3. Dusting with Aluminum Powder for hard or dark colored surfaces as well as mirrors and metal surfaces. Color contrast Magnetic 4. Use of Cyancacrylate (Super-Glue) fuming ” super glue” fumes react with water and other fingerprint constituents to form hard whitish deposit.

Methods of Detecting Fingerprints Cont. 5. Use of Iodine Fuming techniques -Iodine crystals sublime (5-7g)--goes from solid to gas at room temperature. -Gas sticks to print-not permanent--need to take pictures 6. Use of ninhydrin -Reacts with the protein in the print -Often used on porous surfaces 7. Use of Silver Nitrate -Reacts with sodium chloride (salt) in the oil. 8. Use of Gentian Violet -Fluoresce the print--print will glow 9. Use of Laser Technology -Using dyes and wave lengths of light, you can get the print to glow. Preservation of Prints -Prints are often lifted with tape and them placed on a card -Contrasting background -Photograph is taken Digital Imaging -Picture id transferred to a digital image. -Once the image is stored, it can be manipulated for better resolution. -Used to compare prints side by side -Only good as image produced  In modern labs and criminal investigations, lasers and alternative light sources are used to view latent fingerprints. It was first used by the FBI in Since lasers can damage the retina of the eye, special precautions must be taken and a filter used.

Other Prints DEars--shape, length and width DFace--pictures being used in Florida to find criminals DVoice--electronic pulses measured on a spectrograph DFeet--size of foot and toes; lines of the feet DShoes--can be compared and identified by type of shoe, brand, size and year of purchase DEars--shape, length and width DFace--pictures being used in Florida to find criminals DVoice--electronic pulses measured on a spectrograph DFeet--size of foot and toes; lines of the feet DShoes--can be compared and identified by type of shoe, brand, size and year of purchase

Other Prints Palm--lines can be identified and may be used against suspects.

Other Prints Foot Prints are taken at birth as a means of identification for infants.

Other Prints The study of lip-prints is called cheiloscopy Lips--display one of five common patterns  Short vertical lines  Long vertical lines  Rectangular lines that may crisscross  Diamond  Branching The study of lip-prints is called cheiloscopy Lips--display one of five common patterns  Short vertical lines  Long vertical lines  Rectangular lines that may crisscross  Diamond  Branching

Other Prints DThe use of lip prints is not yet firmly established in our courts. DTwo ways to potentially use lip prints: C1- print patterns for identification C2- chromatography to match lipstick marks DThe use of lip prints is not yet firmly established in our courts. DTwo ways to potentially use lip prints: C1- print patterns for identification C2- chromatography to match lipstick marks

Other Prints Teeth--bite marks are unique and can be used to identify suspects. These imprints were placed in gum and could be matched to crime scene evidence.