Fingerprints – How Fingerprints Solve Crime

Fingerprints are something most people don’t spend too much time thinking about on a daily basis. In fact, unless someone is trying to remove pesky fingerprints from furniture or mirrors, it’s unlikely an average person thinks about fingerprints at all.

However, for some, fingerprints are a vital part of their work life. Law enforcement officers and forensic specialists spend hours thinking about how fingerprints solve crimes, and trying to find, collect, record and compare these unique identifiers that can connect a specific person to a specific crime. These individuals understand that a basic human feature that most people take for granted, can be one of the most effective tools in crime solving.

Every person is born with their own unique set of fingerprints. No two fingerprints have ever been found to be exactly alike; not on identical twins (although these are extremely similar), not even on a person’s own hand. The unique whorls and lines that make up an individual’s fingerprints are formed in the foetal stage and remain the same throughout the entire life span. This makes for a unique mark that can positively identify one individual against another, particularly useful when a person of interest already has a recorded set of fingerprints on file with police, military or other government institutions.

Fingerprints are made up of a collection of swirling lines. The way these lines form and pattern themselves is what makes each fingerprint unique. Despite the incredible number of different fingerprints, there are only seven different types of lines that make up fingerprints. These lines may start, stop or split at any place within the print. The formations, angles, lengths, heights and widths make billions and billions of different prints.

With their unique qualities, it becomes easy to see how fingerprints can help solve crimes. Leaving a fingerprint is like leaving a calling card at the crime scene. There are a few different ways fingerprints get left behind by careless crooks. The most common way is from fat or oil that is transferred from the finger to an object like a doorframe or table. Amino acids from the finger may also leave a discernable mark. Fingerprints can also be detected as an impression in a soft substance such as putty. Finally, they can be made by a substance on the finger such as blood or paint.

Uncovering fingerprints to help solve a crime can be done in a few ways. Adhering powders to fresh fingerprints will cause the powder to stick to the grease and make the fingerprint visible. Another method is by using a few drops of cyano-acrylate or superglue. When these drops are heated, they vaporized and the smoke attaches to the fingerprint leaving a clear white print. Specialised crime scene laboratory equipment can also find fingerprints, but not all authorities have access to all equipment.

Fingerprints can be saved for further investigation in a number of ways, including:

  • take a photograph of the print
  • store it on a rubber lifter or tape
  • keep the original ground the print is on
  • copy the print using digital technology

Ideally, from a crime-solving perspective, it is hoped the interconnected nature of our society will eventually lead to having all fingerprint databases linked for easy cross-reference. However, there are several issues to be dealt with, such as funding, jurisdictional bickering, security and privacy to consider before such a fingerprint system can exist. For more information on finger printing please feel free to visit our site at