Fingerprint Fun

A fingerprint is an impression of the pattern of ridges of a finger. Because no two people have the exact same patterns of finger ridges, that unique pattern can be linked to a fingerprint left on an object. Fingerprints collected at a crime scene can be used in forensic science to identify a suspect, victim or any other person that may have touched a surface.

The science of fingerprint identification is also known as dactyloscopy. This term derives from the ancient Greek words daktylos which means “finger” and skopeō “I look at”. Fingerprints have been recorded as used since Ancient Babylon where business people would press their fingerprints into clay tablets to record business transactions.

The classification system used through most of the 20th century in the United States was developed in India in the late 1800’s by Sir Edward Henry. This is known as the Henry Classification System. This system breaks fingerprints down into three main categories: Loop, Whorl and Arch. The Loop, Whorl and Arch types of fingerprints represent 60-65, 30-35 and 5 percent of all fingerprints, respectively. This system is used more to exclude fingerprints based on their designs rather than to identify a single fingerprint.

Fingerprints at a Crime Scene: Fingerprints can be plastic, patent or latent. Plastic prints are left in a soft surface like wax or putty. Patent prints are visible to the eye and occur when your finger first touches a colored substance like ink and then presses against a surface and leaves a mark. Latent prints are invisible to the eye and are made up mostly of oils and sweat on your skin.

Forensic scientists use many methods to make latent prints visible. On a solid surface like a mirror or countertop a fine dust can be applied that will stick to the oils left behind in a fingerprint. On a bumpy or uneven surface a fingerprint can be revealed by using heated superglue! On a surface like paper, specific chemicals can be used to develop the fingerprint so that it becomes visible.

The FBI maintains a fingerprint and criminal history database called the Integrated Automated Fingerprint Identification System or IAFIS. Fingerprints are voluntarily submitted to IAFIS from local, state and federal agencies and come from criminal and non-criminal sources.

Put your investigative skills to the test in the exhibit CSI: The Experience, created in cooperation with the hit CBS franchise. You’ll use cutting edge forensic science and technology to investigate a crime scene, analyze evidence and build a case. Discover if your skills solve the crime … or leave the case cold!

CSI: The Experience was developed by the Fort Worth Museum of Science and History with support from CBS Consumer Products, the cast and crew of the television show, the American Academy of Forensic Sciences, and the National Science Foundation. ® CBS © 2000-2010 CBS Broadcasting, Inc. and Entertainment AB Funding LLC. All Rights Reserved.