A latent print examiner is a crime scene investigator who looks for fingerprints on items and compares them to a central database. Latent fingerprints, which are imprints made distinct ridges in the skin that become coated with sweat and are not visible to the naked eye, are not always visible. Unless there is a severe injury, every person’s fingerprints are unique and appear the same from 16 weeks of gestation until death.
Chemical and physical fingerprint identification techniques are one of the main responsibilities of a latent print examiner. Fingerprint analysis is another aspect of the job. A fingerprint examiner looks for the many unique characteristics that each fingerprint possesses. Because each fingerprint contains over 100 unique identifiers, even a partial print can be used as evidence. The examiner must have a keen eye and thorough understanding of the methods and technology used in this field of criminology because latent prints can easily be smudged, wiped, or affected certain events.
There are several ways to make latent fingerprints visible. Dusting with pigment, using chemicals like ninhydron or cyanoacrylate vapors, and inking are all valid methods that a latent print examiner can employ. The composition and sensitivity of the surface on which the prints are made, as well as the climate and the size of the object being examined for fingerprints, all influence the method of visualizing a fingerprint.
After the fingerprints have been identified and analyzed, the criminologist can compare them to a database of prints or prints taken from a person suspected of committing the crime. Fingerprinting entails dipping a suspect’s fingers in ink and rolling them on paper in a precise, scientific manner. The latent print examiner can then scan the suspect’s fingerprints into a computer and compare them to prints found at a crime scene, either ruling out or confirming the suspect.
The requirements for becoming a latent print examiner differ depending on where you work and what you do. For example, in the United States, it is widely accepted that to work in this field, one must be certified the International Association of Identification (IAI), which has affiliates in more than a dozen other countries. Despite the fact that employment requirements vary location, certification from the IAI is accepted almost everywhere.