Fingerprints

patent prints

made after a finger comes in contact with a visible material

-blood, ink, grease, paint, etc

plastic prints

indented visible impressions left in soft material

-clay, wax, soap, vaseline, etc

latent prints

invisible prints that must be processed to be seen

-sweat

the core

approximate center of pattern

type lines

diverging ridges that surround the core

the delta(s)

triangular shape area where type lines meet

plain arch

-ridges start on one side, rise in the middle, and exit on the other side

-no core or deltas

tented arch

ridges start on left, SHARP rise in middle and exit on right

plain loop

ridges start on one side, loop around, and leave the same side

ulnar loop

-opens towards the pinkie

-right/left

radial loop

-opens towards the thumb

-most often index finger

-right/left

(plain) whorl

-circular pattern radiating around center of finger

-2 or more deltas

central pocket loop whorl

Line between deltas does not cross circular part of ridge pattern

double loop whorl

two opposing loops side by side

accidental whorl

combo of any two patterns except plain arch

ridge ending

short ridge

fork or bifurcation

hook

eye

dot or island

crossover

bridge

enclosures

specialty

ACE-V

-Analysis

-Comparison

-Evaluation

-Verification

physical developments

-powder dusting w/ colored, fluorescent, and/or magnetic powders for dry, smooth, non-porous surfaces

-small particle reagent for hard surfaces that are or have been wet, sticks to fats/oils of prints

chemical developments

-cyanoacrylate (superglue)

-iodine fuming

-ninhydrin

ninhydrin development

reacts with amino acids in fingerprint residue and yield blueish purple color, useful on porous surfaces

sequential developments

multiple steps in order to get most information while maintaining as much evidence as possible

AFIS

automated fingerprint identification system

-scanning devices convert fingerprints into digital images and a search algorithm determines possible matches

-final decisions made by a trained examiner ALWAYS

fingerprint conclusions

-source identification

-inconclusive

-source exclusion

iodine fuming

interacts w/ oily residues to give deep brown print, do not las long (must be photographed)

cyanoacrylate

Superglue that is used to capture fingerprints on nonporous surfaces like glass and plastic.