Fingerprints - A Unique Identity

Jul 29, 2012 By Written for Youngzine by INTERPOL

Imagine you’ve picked up a glass of water and taken a drink. Did you know that the fingerprints you leave behind on the glass are unique to you? And that they will never change during the course of your life?

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Since everybody’s fingerprints are different and unique, they are an ideal method of identification. July 28 marks the 154th anniversary of the first modern use of a fingerprint for identification, when a magistrate in India required a businessman to mark a contract with his handprint as a signature.

Since then, the practice has become more common. Fingerprints are included on passports for identification. You can also use your fingerprint to open some car doors, to enter an office, and to turn on a computer instead of using a password.

By far, the most well-known use of fingerprints is by police, to link crime scenes to suspects. INTERPOL, the world’s largest international police organization based in France, helps police worldwide to identify and bring to justice some of the most dangerous criminals.

An officer checking for fingerprint matches in the INTERPOL database

INTERPOL has a database containing more than 160,000 fingerprint records submitted by its member countries. These fingerprints are collected from crime scenes, and from known and suspected criminals. Police run fingerprints found at a crime scene through the database to see if they can find a match, or a ‘hit’. Last year, more than 1,800 hits were made.

What makes them unique?

Fingerprints are created by the sweat in your hands. They are the easiest to extract from flat, nontextured surfaces like glass and plastic.

The procedure for collecting fingerprints at a crime scene is actually quite similar to what you see on popular television shows, although the results usually come back in days, not minutes. The fingerprint is dusted with a white, black or colored powder to make the print visible, then lifted and sent to a laboratory, where it is enhanced using chemicals and then entered into a database to check for possible matches.

Although fingerprints are a great crime-fighting tool, they are used together with all types of evidence, including DNA, bullets and items left behind by the criminals, to build a stronger case.

The INTERPOL fingerprint database has been used to catch many international criminals. In one case, a Belgian ship was hijacked, then released, by Somali pirates in 2009. The fingerprints lifted from the ship by Belgian police were input into the INTERPOL database. Two years later, six Somalis were found adrift at sea and rescued; their fingerprints were taken by Seychelles police and also input into the database. The system detected a match between one of the rescued men and one set of prints taken from the hijacked ship, and a criminal case was started against him.

To learn more about the role of fingerprints in police work and test your skills at matching fingerprints, visit INTERPOL Student Zone.