Introduction
What are the ridged skin designs on fingertips called?
Fingerprints.
Which method uses adhesive to transfer a latent print from a non-porous surface?
Lifting tape (adhesive tape).
Name the three primary fingerprint pattern types.
Loops, whorls, and arches.
What does powder dusting reveal on a surface?
It reveals oily sweat ridge patterns by causing powder to adhere to fingerprint residue.
List a capabilities or feature of AFIS.
AFIS stores large digital fingerprint databases and can rapidly search and compare fingerprints for potential matches.
Name two reasons fingerprints are useful for identification.
They are unique to individuals and remain permanent throughout life. They are also used for biometric security and forensic identification.
How were fingerprints take before the digital era?
The ink-and-paper method.
Rank the three primary fingerprint pattern types based on how often they appear percentage wise.
Loop, whorle, arch
Name the chemical reagent that reacts with amino acids in sweat to reveal prints on porous surfaces. It leavea purple color behind.
Ninhydrin.
What does AFIS stand for?
Automated Fingerprint Identification System.
Explain why identical twins have identical fingerprints.
Fingerprints are influenced by genetics (DNA), which identical twins share, and the fingerprint is created before environmental factors have a chance to influence them.
Which modern digital method captures fingerprints electronically using a glass plate with sensors?
Live Scan.
List the % of the three primary fingerprint pattern types based on how often they appear.
Loop - 65%
Whorle - 30%
Arch - 5%
Iodine fuming process leaves behind a deeper red colored trace, true of false?
False, the trace is brown in color.
Summarize three scientific claims about fingerprint validity mentioned in the text.
Fingerprints are unique, remain persistent throughout life, and have an extremely low probability of coincidental matching.
At what stage of life do fingerprints form, and what two influences affect their formation?
Fingerprints form before birth during fetal development. Their formation is influenced by genetic and environmental factors.
Describe two ways latent prints are made visible at a crime scene
Latent prints can be made visible by dusting with fingerprint powder or by using chemical treatments such as ninhydrin or cyanoacrylate fuming.
Define and give an example of a patent print and a plastic print.
A patent print is a visible fingerprint, such as one made with blood or ink. A plastic print is a three-dimensional impression left in a soft material such as wax, clay, or paint.
Explain how cyanoacrylate fuming works and on what type of surfaces it is most effective.
Cyanoacrylate vapors polymerize on fingerprint residue, producing a visible white print. It is most effective on non-porous surfaces.
Define "uniqueness" as it applies to fingerprints and give the estimated statistical probability mentioned for two people sharing identical fingerprints.
Uniqueness means that each person's fingerprints have a distinct pattern. The probability of two people having identical fingerprints is extremely low—estimated at less than one in several billion.
Explain when photography is used in fingerprint collection and why specialized lighting matters.
Photography is used to document fingerprints, especially at crime scenes. Specialized lighting enhances the visibility and detail of fingerprints for analysis and courtroom presentation.
What distinguishes a whorl from an arch or a loop? Include delta information in your answer.
A fingerprint whorl is distinguished from an arch or a loop primarily by having two or more deltas and ridge lines that form a complete circuit, circle, or spiral pattern.