“Every human being carries with him from his cradle to his grave, certain physical marks which do not change their character, and by which he can always be identified – and that without shade of doubt or question. These marks are his signature, his physiological autograph, so to speak, and this autograph cannot be counterfeited, nor can he disquise it or hide it away, nor can it become illegible by the wear and mutations of time.” Pudd’nhead Wilson, Mark Twain

Mixture of water, oils, salt, and dirt

Alphonse Bertillon (1902) – credited for solving the first murder using fingerprints, also first to document incoming prisoners with a photograph

Galton and Henry (1888) – developed system for classifying fingerprints still used in US today

Ivan Vucetich (1891) – began taking first ten cards

3 Basic PatternsLoopWhorlArch

One or more ridges entering from one side, curving and going out same sideLoop even if only one ridge exits the side it enters2 subgroups

Radial: opens to thumb (radius) Ulnar: opens to pinky (ulna) **more

common65%

Must have atleast 2 deltas and a core4 subgroups

Whorl Central pocket Double Accidental

20%

Least common, simplestRidges enter one side and exit the otherNo delta or core2 subgroups:

Plain arch Tented arch

Sometimes confused with loopsNo delta or core

Plain Arch

Tented Arch

Method developed by Edward Henry to classify all sets of ten fingerprints

1,024 groups Manual comparisons still very common

Primary Classification› Identify any whorls› Rt Index Rt ring Lt thumb Lt middle Lt

little16 8 4 2 1 +1

___________________________________________________Rt thumb Rt middle Rt little Lt index Lt ring

16 8 4 2 1 +1

Whorl on left thumb and right middle finger› Rt Index Rt ring Lt thumb Lt middle Lt little

16 8 4 2 1 +1

___________________________________________________Rt thumb Rt middle Rt little Lt index Lt ring

16 8 4 2 1 +1

0+0+4+0+0+1 = 5-------------------------0+8+0+0+0+1 = 9

Loops Whorls Arches

Ulnar Radial Plain Other Plain Tented60% 5% 20% 10% 4% 1%

Minutiae – tiny ridge characteristics

8-12 points of minutiae usually provide enough for conviction

No amount legally required Print will have 150-200 minutiae, but

prints must be rolled properly

So, do you think you can alter your fingerprints?

Plastic prints – (indented or molded) 3-D› Paint, putty, soap, wax, gum, candy bar

Visible prints – print on colored material

Latent prints – invisible and must be developed (deposits of perspiration and oil)

Dusting› Hard, nonabsorbent surfaces

Chemical methods› Soft, porous surfaces (paper, styrofoam)› Iodine – reacts with fatty oils on finger› Ninhydrin – reacts with amino acids and turns

orange or purple› Silver nitrate – reacts with salt and turns into silver

chloride which then turns into dark silver oxide (photographs)

› Superglue – cyanoacrylate ester adheres to create permanent print

Alternate Light Sources

When only one piece of evidence, use the tests that cause the least damage to the print.

Timeline

Even twins have different fingerprints Papillae under the epidermis cause the

friction ridges to occur

Digital enhancement IAFIS (Integrated Automated

Fingerprint Indentification Systems) Fluorescent dyes Lasers IAFIS (Integrated Automated

Fingerprint Identification System) › More than 46 million records› Live scan devices