Eye for Evidence: The Importance of Fingerprints Part II

Fingerprints can be one of the best clues and the most substantial evidence you may find aside from DNA. My last blog covered the importance of classifying-identifying-fingerprints. Backing up a little, you book someone, take their fingerprints and those ten print cards are classified so that each and every finger's pattern is identified. Now what? Now, those prints are on file and if a latent print is found at a scene it is compared to those ten print cards. However, it is not as simple as that and though television has made the process look quick, cool, and fun it isn't always exactly that. 

I love mapping out a print and spending hours comparing it-but that it isn't everyone's cup of tea. The work pays off though and there is nothing like that feeling when you find a match especially when it is a huge part of the case. 

When I use the word "mapping" I am referring to that tedious task of pointing out every little detail on the print. You have to count the ridges, and determine what characteristics are unique enough to possibly constitute comparing it to known prints. (Note: never look at suspect's prints first and then at the latent that was found-always go in blindly. Look at the latent first, map it out then run it/compare it to known samples. This way way there no one can say you were trying to find that particular persons prints. Make it as unbiased as possible-if they are the bad guy the print will reveal that.) 

Without getting into the minute details of analyzing a print, it should be noted that a latent print must have at least 7 to 10 points of unique characteristics in order to constitute comparing it to known prints. From there, you must have an equal match of 10 to 12 characteristics in order for the print to be considered a bona fide match and hold up in court as an identifier. When you do have one it pays off. 

I can recall one instance when some illegal narcotics were hidden on a subject's property. They were in neat little jars that as we all know were not meant for display purposes but most likely distribution. The subject insisted it was not his and he had never seen the jars...however the large thumb print I lifted said otherwise. It is in those moments that all of that hard work pays off.