Montshire Minute: Fingerprinting

Originally aired during the week of February 21, 2005

Monday

Which category do you fall under - tented arch? Ulnar loop? Or are you more of a "central packet loop" kind of person? Unless you are a police detective or a forensic scientist, these terms may not mean much to you. Each term refers to one of eight basic fingerprint patterns found in humans. When you look closely at your fingertips you can see the distinctive patterns made by ridges of skin, like miniature topographical maps. Scientists think these "papillary ridges" are there to give us a better handle on objects, the same way tire treads are engineered to "get a grip" on the road. It took a while for researchers to discover that each person's fingerprints are unique. This has led to fingerprinting as a method of identification, especially in police investigations. So, maybe it's a good thing you don't know if you're a "plain whorl" or a "double loop."

Tuesday

Over the centuries, curious people have contemplated the tiny ridges of skin on their fingertips. Prehistoric carvings of hands with ridge patterns were discovered in Nova Scotia and on walls of Neolithic burial passages on an island off the west coast of France. In ancient China, it is thought that fingerprints on clay seals were used as a sort of official signature. In 1823, a German professor noted that the "papillary" ridges on human fingers seemed to follow distinct patterns. But it was a while before fingerprinting was used scientifically, as a way of personal identification. Learn more about how police detectives use fingerprints in crime investigations at the Montshire Museum's new exhibit Crime Lab Detectives. This exhibit challenges you to examine a crime scene, read the clues, and determine the identity of a neighborhood burglar. Get your thinking caps ready!

Wednesday

In the late 1800s researchers began to realize how diverse human fingerprint patterns really were. Dr. Henry Faulds, who worked at a hospital in Tokyo, noted the wide variety of individual fingerprint patterns. It was even suggested that fingerprints found at a crime scene might provide clues to the identity of the culprit. Then, William James Herschel, writing in Nature magazine, disclosed that he had used fingerprints for 20 years as a way of identifying prisoners. It was Sir Francis Galton who established that the ridge arrangement on every finger of every person is different, and that these ridge patterns never change through a person's life. Sir Edward Richard Henry, who later became commissioner at Scotland Yard, developed a system of eight types (named, naturally, the "Henry system") which is still used by crime investigators.

Thursday

Sir Francis Galton thought fingerprints might be used to determine heredity and racial background. He discovered that fingerprints offered no basic clues to an individual's genetic history, but he did prove that fingerprints don't change over the course of an individual's lifetime, and that (practically speaking) no two fingerprints are exactly the same. He calculated the odds of two individual fingerprints being the same as 1 in 64 billion. The first criminal fingerprint identification came in 1892 in a murder case. A woman named Rojas murdered her two sons and slightly cut her own throat in an attempt to place blame on another suspect. But she left a bloody fingerprint on a door post, revealing her identity. Use your own sleuthing skills at Crime Lab Detectives, a new exhibit at the Montshire Museum. Fingerprints of the suspects are just some of the clues you'll evaluate as you try to identify a neighborhood burglar.

Friday

Whorls, arches, and double-loops may sound like rides at an amusement park. Actually, they are names of line patterns that make up a human fingerprint. They are "permanent" in that they are formed in the fetal stage, prior to birth, and remain the same throughout a lifetime. It was once thought that a fingerprint was an infallible means of personal identification it became a main tool to identify criminals. Some Science historians question the value of fingerprints, arguing prints found at a crime scene are often "partial prints" and that fingerprinting is not subject to scientific scrutiny. Learn more about how detectives still use fingerprints in crime investigations at the Montshire's new exhibit Crime Lab Detectives. This exhibit challenges you to examine a crime scene, read the clues, and determine the identity of a neighborhood burglar. Get your thinking caps ready!