Fingerprint Alterations Present Unique Challenge to Investigators

Law enforcement agencies have been using techniques to record and identify fingerprints for many years, with records going back almost a century available to crime scene investigators. However, individuals hoping to avoid identification based on their fingerprints and to mislead law enforcement have been employing a variety of different techniques to alter their fingerprints.

FBI examiners have found cases where criminals had intentionally altered their fingerprints, sometimes on their own and occasionally with the help of medical professionals. These alterations distort the usual fingerprint pattern and can make it difficult to identify those fingerprints when later examined.

The FBI has undertaken a study with the intention of recording the different deliberate methods of fingerprint mutilation in the hopes of improving its ability to identify altered fingerprints.

Individuals who have altered their prints were arrested for everything from drug trafficking to violent crimes and many are seasoned criminals who represent a dangerous threat to the general public. Being able to categorize and identify altered fingerprints is of the utmost importance for law enforcement officials to continue doing their jobs effectively.

A helpful part of this process has been the categorization of the different kinds of mutilation used by criminals. These include cutting lines into the skin, vertically or in a z-pattern, in an attempt to both remove portions of the fingerprint and cause the skin to heal in a fashion which overlaps the old print and alters it significantly. Subjects have also been known to burn their fingerprints using both heat and chemical sources. The intention here is to scar or entirely destroy the fingerprint and prevent identification.

These are just some of the methods that have so far been identified, with altered fingerprints showing up whose origin analysts are unable to identify. Law enforcement agencies can assist the process by continuing to report altered fingerprints and thereby helping to significantly improve efforts to identify and categorize altered prints.