Fingerprints Flashcards
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
What are the 4 subtypes of whorls?
Plain (P)
Central Pocket loop (C)
Double Loop (d)
Accidental (x)
What are the tracings for whorl prints?
Inner (I)
Meet (M)
Outer (O)
What is an Ident?
2 prints that are considered a match
What is erroneous ID?
when 2 prints are compared and said to be Ident when they are not (bad ident)
What are the 3 major palmprint areas?
Thenar
Interdigital
Hypothenar
What are included in major case prints?
1) extreme sides of palms/joints
2) tips of fingers
3) sides of fingers
What are the 2 impression types?
1) rolled
2) plain (slapped/flat)
What is a rolled impression?
fingers are individually recorded
What is a plain impression?
4 fingers taken simultaneously, thumbs individually.
Prints not rolled just placed down
Why are plain impressions taken alongside rolled?
they are recorded on the bottom portion of the card to verify accuracy of rolled prints
What is the blocking out for Ulnar loops?
\ for blocks 1-5
/ for blocks 6-10
What is the blocking out for Radial loops?
R for block 2 and 7
r for all other blocks
What is the blocking out for Plain arch?
A for blocks 2 and 7
a for all other blocks
What is the blocking out for Tented arch?
T for blocks 2 and 7
t for all other blocks
What is the blocking out for Whorls?
W for all blocks
