Integumentary Notes – Fingerprints
Fingerprints – “______”
- caused by the presence of tiny ______in the outer skin
o they develop before birth (usually between 2-3 months in womb)
§ see animations of their creation at: http://www.clpex.com/images/Animations/Fusion.htm http://www.clpex.com/images/Animations/Minutia.htm
o contain rows of pores that connect to ______glands
§ Latent (______) fingerprints are created when sweat and oils are transferred to a surface
o increase ability to ______and reduce slippage
o there are hills (______) and valleys (______)
- the arrangement and number of these ridges are unique to every individual
o each fingerprint has at about ______individual ridge characteristics
o even identical twins have different fingerprints (though they are very similar)
o two identical prints have never been found
o calculated that probability of finding identical prints is 1 in ______
- fingerprints can be altered
o must cut more 1-2 ______beneath skin’s surface to permanently damage
§ must damage the ______
§ otherwise, ridge patterns will reappear as before
o removed by ______
§ however, new scar tissue will become the new identifier
§ Example – John Dillinger (______gangster)
· Tried to use acid to remove ridge patterns, but his wounds healed, and comparisons between previous fingerprints and new fingerprints showed at least _____ individual identifiers
- one family in America has a genetic mutation where they do not have fingerprints
However, they do have a few characteristic ridges, which can help identify them
Images of Fingerprint patterns
Three Main Categories:
______– plain and tented
______– ulnar and radial
______– central pocket loop, plain whorl, double loop, accidental
Accidental Whorl
Fingerprint ridge patterns
- Best way to determine is by looking at “deltas” and “cores”
- ______– triangular pattern (blue, lower-right box)
- ______– end of ridge, with other ridges wrapped around it (red, upper-left box)
Three main categories
o Arch – 5% of fingerprints
§ Ridgelines start from one side of the fingertip, rise at the center, and exit on the other side of the fingertip
· Usually ___ true deltas
PLAIN ARCHTENTED ARCH
§ ______– rounded at the top
§ ______– pointed at the top
o Loop – 60-65% of fingerprints
§ Ridgelines start and end on the same side of the fingertip
· Has _____ delta
§ Radial – opens toward the thumb (and the ______bone)
- ______
§ Ulnar – opens toward the little finger (and the ______bone)
o Whorl – 30-35% of fingerprints
§ Ridgelines are circles that do not begin or end on either side of the fingertip
· Has ______deltas
§ Plain – at least one ridge makes a complete circle
· Line formed between the two deltas ______intersect ridge forming a complete circle
Plain whorl / Two deltas marked / Line joining deltas§ Central pocket – complete circle is offset – usually much higher or left/right than a plain whorl
· Line formed between the two deltas ______intersect ridge forming a complete circle
Line joining two deltas -Central Pocket Whorl / Line joining two deltas – Central Pocket Whorl / Line joining two deltas – Plain Whorl
§ Double loop – contains ______separate and distinct loops
Double Loop / Arrows pointed to each core / Each loop indicated§ ______– has multiple twists and turns
· Has more than two ______
Ridge Characteristics (also known as ______)
o identity, number, and relative location of characteristics create individuality
o examples:
o most fingerprints have about _____ individual ridge characteristics
§ however, most fingerprints found at a crime scene are partial fingerprints
Minutiae are the discontinuities of the ridges:
· ______- the points at which a ridge stops
· ______- the point at which one ridge divides into two
· ______- ridges slightly longer than dots, occupying a middle space between two temporarily divergent ridges
· ______- two ridges which cross each other
· ______- the inner point, normally in the middle of the print, around which swirls, loops, or arches center. It is frequently characterized by a ridge ending and several curved ridges.
· ______- the points, normally at the lower left and right hand of the fingerprint, around which a triangular series of ridges center.