Over 100 years ago, fingerprinting was adopted by the New York City Civil Service Commission for applications. Only a couple decades later, the FBI began using fingerprinting, amassing a giant collection of fingerprint records. DNA evidence is increasingly used in forensics, but the science of fingerprint identification is still heavily used for a myriad of reasons.
According to Onin, fingerprints are the most commonly used type of forensic evidence. Fingerprinting is accurate because fingerprints are unique and permanent. A fingerprint's ridges are completely original. There has never been a recorded case of two people sharing the same fingerprints. Also, the unique characteristics of a person's finger ridges do not change. Fingerprint experts can link a fingerprint's precise characteristics back to an individual, reliably ruling out or incriminating a criminal suspect.
Crime Scene Investigation
Crime scene investigators and forensic specialists collect fingerprints from a crime scene in a variety of ways. Methods of detecting prints include powder and tape, magna brush, ninhydrin, iodine fuming, and silver nitrate. Advances in forensic science means that as long as a fingerprint can be found, specialists will probably be able to process it for identification. Partial or incomplete fingerprints can be processed. Fingerprint evidence is usually pretty fragile, but the technology is improving. According to Science Daily, it's possible to obtain fingerprints from a crime scene even if they have been washed off.
When taken for law enforcement, identification, or employment purposes, fingerprints are scanned and stored in giant digital databases. Because of advances in fingerprint scanning technology and computers, fingerprint databases make it easy for law enforcement officials to exchange criminal evidence and information.
Automated Fingerprint Identification
Many fingerprint databases are paired with automated fingerprint identification systems to match unknown fingerprint samples against the known fingerprints on file. The FBI's fingerprint database - called the Integrated Automated Fingerprint Identification System - is the largest in the world. Automated fingerprint identification can generate a list of suspects for law enforcement officials with a 98-100% accuracy. They save lots of time, since fingerprints can be matched within seconds. In addition, because the results are computer-generated, it eliminates the risk of human-error.