Fingerprints
From invisible trace to damning evidence – how they solve crimes
What is a fingerprint, and why is it so crucial?
In forensics and the true crime genre, fingerprints refer to the unique pattern of ridges and furrows on a person's fingertips. These prints can be left on various surfaces and often constitute crucial evidence in a criminal investigation. Every person's fingerprints are recognized as unique, even in identical twins, and remain largely unchanged throughout life. This makes fingerprints an exceptionally powerful tool for personal identification.
Invisible and clear: types of fingerprints at scenes
The discovery of a fingerprint at a crime scene can directly link a person to the location or to objects involved in a crime, which is essential in presenting evidence. These prints can be latent fingerprints – invisible to the naked eye – and therefore require special development techniques, such as the use of powder or chemicals. Alternatively, the prints can be visible if the finger has been in contact with substances like blood, paint, or other materials. Additionally, there are plastic prints, which are three-dimensional impressions left in soft materials, such as wax or wet paint.
Technicians: from fingerprint collection to matching
Forensic technicians meticulously secure evidence by locating, photographing, and collecting these fingerprints, either by lifting them with special tape or by securing the entire object on which the print is found. Subsequently, a thorough fingerprint analysis is conducted by experts. They compare the collected prints with reference prints from suspected individuals or search for matches in extensive national and international fingerprint databases. A match between a fingerprint from a crime scene and a person registered in a fingerprint database can constitute a crucial breakthrough in a case. It can potentially identify a perpetrator, confirm a suspect's presence at the crime scene, or even help exonerate an innocent person.
Fingerprints: why context and quality matter most
Although fingerprints constitute strong evidence in forensic science and investigations, their evidentiary value always depends on the context. A fingerprint only proves that a person has touched a given surface, but not necessarily when or under what specific circumstances the contact occurred. Furthermore, the quality of a recovered fingerprint can vary significantly; smudged or partial prints can be difficult, or in some cases impossible, to identify with certainty. The absence of fingerprints at a crime scene does not necessarily rule out a person's presence, as, for example, the use of gloves or the nature of the surface can prevent prints from being left or preserved.
In the DNA age: why fingerprints remain crucial tools
Despite technological advancements and the development of other advanced identification methods, such as DNA evidence, fingerprint analysis remains a fundamental and often indispensable part of modern criminal investigation. The unique ability of fingerprints to individualize people and thereby link them to criminal acts ensures their status as a persistently relevant tool in biometric identification and in the pursuit of truth and justice. It continues to play a central role in solving countless crimes worldwide.
How Have Fingerprints Revealed Perpetrators in Cases of Burglary and Violent Crime? Read Concrete Examples of Fingerprints in Action. Explore Our in-Depth Cases Below.