How Fingerprinting Improves Criminal Investigations

Female investigator examines fingerprint on computer from a crime scene

One of the most important parts of a forensic investigation is fingerprinting. As fingerprints are unique to each individual, they serve as a way for law enforcement agencies to identify a suspect, as well as help build a case in court. Many students in criminal justice degree programs are interested in learning more about fingerprinting, as it is widely used in all forms of law enforcement.

History of fingerprinting

While the science of recording fingerprints can be traced back thousands of years, it was not until the late 1800s that it began to be used to fight crime. Since then, however, it has been used in thousands of legal cases.

Ancient history – According to some experts, fingerprinting can be dated back to 2000 B.C. It is believed that Babylonians required fingerprints to be inked onto contracts to avoid forgery. Around the year 250 B.C., Chinese officials used fingerprints to seal official documents.

Early theories – A surgeon by the name of Henry Faulds originally discovered that the ridges and loops on a person’s fingertips are unique. In 1880, he published an article in a science journal that explored the use of prints for personal identification. Faulds is also credited for taking the first fingerprint, lifted from an alcohol bottle.

Complete history – The National Institute of Justice has a thorough guide to fingerprinting on its website that students earning a criminal justice bachelor’s degree may find useful while learning about fingerprinting.

Fingerprinting and forensics – A timeline of the use of forensics shows that fingerprinting is one of the oldest methods of investigating a crime using science.

Fingerprinting technology

Since its initial introduction in criminal investigations, fingerprinting has evolved a great deal. Originally, prints were taken with ink and placed on paper, which was filed away with personal information about an individual. Today, the Internet and computers allow law enforcement officials to place prints in a massive database run by the Federal Bureau of Investigation (FBI) that can be accessed from anywhere in the world. The technological advances in fingerprinting have also had a major impact on identifying prints at crime scenes as well, not just in recording them from a person.

Ink prints – There are only two primary methods to record a fingerprint. These are done to ensure that the impression is made in a legible and copy-able manner that experts and forensic scientists can study.

Digital improvements – Computing technology has allowed law enforcement to improve on fingerprinting and biometrics a great deal in the past few decades. The FBI runs a database, called the Integrated Automated Fingerprint Identification System (IAFIS), that stores digital fingerprints, and the corresponding criminal histories that go with them. From mug shots to aliases, the system holds information about the fingerprinted individuals that may help investigators working on criminal cases.

DNA biometrics – DNA was used for the first time as evidence in a criminal case in 1988. While fingerprinting is still an important and commonly used tactic used to identify a suspect, scientists discovered that DNA biometrics also help to strengthen criminal cases. Like fingerprints, DNA is specific to each individual. DNA evidence can be pulled from strands of hair, blood or even sweat at crime scenes.

Using fingerprints outside of criminal investigation

While fingerprints are useful in investigations and as evidence in criminal cases, they have other functions as well. They can be used to identify missing persons, or as a safety precaution in immigration and military cases.

Immigration services – The U.S. requires all foreign-born individuals seeking an imigrant visa to provide finger prints for the purpose of verifying identity and conducting criminal background checks.

Military identification – The U.S. armed forces have used dog tags for decades to identify soldiers. However, tags can be lost, stolen, or switched. Fingerprints can be used to identify soldiers that are injured, killed, or missing in action.