Forensic Science Fingerprints

fingerprints are unchanged throughout a lifetime

second principle of fingerprints

fingerprints can be classified

third principle of fingerprints

fingerprints are unique

first principle of fingerprints

pattern if ridges enter and exit on the same side

pattern with one delta and one core

loop

ulnar

ridges enter and leave towards the pinky

radial

ridges enter and leave towards the thumb

pattern with one or more cores and at least 2 deltas

whorl

pattern when ridges enter and leave on opposite sides

pattern with no deltas or cores

arch

bifurcation

the division of something into two branches

Type of whorl that looks like there is a spoon in the center

type of whorl when deltas are on different ridges

pocket

type of whorl when deltas are on the same/very close ridges

pattern if ridges are less than 45 degrees in an arch

plain whorl

pattern if ridges are more than 45 degrees in an arch

tented

3D prints left in soft material

plastic

visible prints

patent

prints that are not visible to the naked eye

latent

fingerprints are created by the ____ on our skin

oil or sweat

prints on biological material (skin) are best developed with ___

chemicals

prints on non-biological material are best developed with ___

powder

Dactyloscopy

study of fingerprints

dactylogram

fingerprint

plain arch

ridges enter on one side and exit on the other side

tented arch

similar to the plain arch, but has a spike in the center

accidental whorl

A mix of different patterns. Cannot be classified as any other pattern.

pocket loop

None of the center core touches the line.

plain whorl

Two deltas, a line drawn between the deltas goes through the central pocket

double whorl

made up of any two loops combined into one print (looks like a wave)

LEFT hand - ulnar loop

opens toward the pinky

RIGHT hand - radial loop

opens toward the thumb

eye

dot/island

fork/bifurcation

bridge

crossover

hook/spur

ridge ending

AFIS stands for...

Automated Fingerprint Identification System

How many minutiae are used to identify fingerprints?

12

An example of a plastic fingerprint is...

soap, wax, or playdoh

An example of a patent fingerprint is...

blood, grease, or oil

3 fundamental principles of fingerprints

1. a fingerprint is an individual characteristic

2. a fingerprint pattern will remain unchanged for the life of an individual

3. fingerprints have general characteristic and ridge patters

remember about ulnar and radial loops

on the left hand a loop that opens to the right would be an ulnar loop, while one that opens to the left would be a radial loop

difference between a plain vs central pocket whorl

if some of the curved ridges touch the line, it is a plain whorl.

If none of the center core touches the line it is a central pocket whorl

difference between a double vs accidental whorl

double loop whorls are made up of any 2 loops combined into one print

accidental whorls contain 2 or more patterns not including the plain arch or does not clearly fall under any of the other categories

fingerprint factoid

60 of people have loop

35 have whorls

5 have arches