How are fingerprints identified and compared in CSI?

How are fingerprints identified and compared in CSI?

Richard Saferstein (Former Chief Forensic Scientist) gives expert video advice on: How are fingerprints detected at a crime scene?; What's the difference between a 'visible fingerprint' and a 'latent fingerprint'?; How are fingerprints preserved in CSI? and more...

We know two things about fingerprints. First of all, all fingerprints come in patterns, and there are three generally recognized patterns. There are loops, swirls, and arches, but that in itself will not identify a fingerprint. What is important are the ridge characteristics that reside in the pattern, and there are numerous ridge characteristics that can be found within the fingerprint pattern, such as a bifurcation, a ridge ending, or an island. It's the number of ridge characteristics and their positions that the fingerprint examiner will look for and compare to a known fingerprint.