We have all seen the crime scenes on television programs. Detectives try to find fingerprints – while criminals make efforts to wipe them away before leaving the scene. How fingerprints are obtained and used, however, is slightly less dramatic, even though some of what you see on TV is true to real life.
BASICS ABOUT FINGERPRINTS
Every person is born with a unique set of fingerprints. According to HowStuffWorks.com, they form from pressure on a baby’s developing fingers in the womb.
The purpose of them is uncertain, but one theory is that they improve our sense of touch, as stated on Phys.org. Another is that they provide traction when we grip items.
According to Crime Scene Forensics, LLC, there are three main fingerprint patterns: loop, whorl and arch. Different patterns exist within each of these categories. Loop patterns account for 70 percent of all fingerprints.
Each ridge of the fingerprint contains pores that are attached to sweat glands, so natural oils and salts from the human body cause a residue to be left behind on items we touch.
HOW FINGERPRINTS ARE OBTAINED AND USED
After someone is arrested, one of the things that will happen during the booking process will be the fingerprinting of the defendant.
The FBI’s Criminal Justice Information Services Division manages an Integrated Automated Fingerprint Identification System that can retrieve fingerprints from anywhere in the country, according to HowStuffWorks. In addition to records of individuals who have been arrested, the system also is used for employment, licenses and social services, so about one out of every six people in this country has a fingerprint record in the system, the website states.
Depending on the conditions at the scene and the surface that the fingerprints were left upon, investigators either photograph the prints or dust a surface and find the print before photographing it.
Digital technology then allows investigators to match the prints found at a crime scene with past records of individuals’ fingerprints. Because each person’s fingerprints are different, it is virtually impossible for two people to have the same ones.