Fingerprints Flashcards
(39 cards)
The 3 types of prints
Loop, Whorl, Arch
Subtypes of Arch pattern
Plain and tented
Subtypes of Loop pattern
Radial and Ulnar
3 ways to classify a print at a scene
Latent, Patent, Plastic
Loop requirements
sufficient recurve, ridge count, and a delta
What is a shoulder?
points at which the recurving ridge turns inwards or curves
What is a sufficient recurve?
The space between the shoulders of a loop that is free of any appendages
What is an appendage?
an attachment to a recurving ridge
What spoils a recurving ridge?
an appendage at a right angle
What is a bifurcation?
one ridge that splits apart at 2 ridges
What is a delta?
point on ridge nearest and directly in fornt of the point of divergence of two typelines
What is a typeline?
2 innermost ridges which start parallel and then diverse and surround or tend to surround patterned area
What are the 6 delta types?
1) Dot, 2) bifurcation, 3) ending ridge, 4) meeting of 2 ridges, 5) short ridge, 6) recurving ridge
If there is more than 1 delta what should you do?
1) Choose delta closest to the core
2) Always choose the bifurcation over other types
What is the core?
The innermost sufficient recurve unless spikes/rods are present within the innermost sufficient recurve, the core will be placed on the shoulder furthest from the delta
What is a ridge count?
The number of ridges between the delta and the core
What is the margin of error for ridge counts?
+/- 2
What is an ulnar loop?
ridges flow towards the pinky
What is a radial loop?
ridges flow towards the thumb
Which hand is on top in a 10-print card?
The left hand
Where is the core placed when there are an even number of spikes/rods?
on the innermost spike/rod that is furthest from the delta
Where is the core placed when there are an odd number of spikes/rods?
on the center spike/rod
What is not included in a ridge count?
The delta and the core
What are the minimum whorl requirements?
minimum 2 deltas with a recurving ridge in front of each
