You might be surprised to hear that fingerprint identification, while a modern forensic concept, was actually successfully used in the first criminal case in 1892. Due to its high reliability, fingerprint identification continues to be the trusted method for solving crimes and eliminating suspects. But it’s not only a useful tool for investigators, you and I can use fingerprints to secure private information or access things quicker. So how exactly is fingerprint data used today, and what is the collection process? It’s more complex than you might think.
Collecting Fingerprints in Investigations
There are three main types of fingerprint collection used in crime analysis. The difference lies in what the fingerprint itself is made up of. Fingerprints from blood, ink, or dirt, that are easily visible are referred to as patent fingerprints. These are also the easiest to identify. When a print comes from residual bodily oils or sweat from the skin’s surface, invisible to the naked eye, this is considered a latent fingerprint. And when a fingerprint has been pressed into a soft surface, it’s referred to as plastic.
Because fingerprints do not change over the course of our lifetime, they are often the strongest piece of evidence that can be collected. The process of retrieving fingerprints will vary depending on the type of print itself, and the surface where it is found.
For retrieving fingerprints from a porous surface like carboard, firewood, or paper, scientists are able to sprinkle chemicals like ninhydrin over the prints and take photographs of the prints as they develop. This chemical turns purple when it comes into contact with human amino acids. For non-porous surfaces like plastic, glass, and varnished wood, forensic teams use a powder-and-brush technique along with lifting tape to pull out a fingerprint. For semi-porous surfaces with grooves or texture, a slightly stronger, silicone casting material is used to lift the print.
Uses of Fingerprint Identification
Once a fingerprint has been obtained and preserved, it can be examined and later used to either identify a victim or eliminate/verify suspects in a case. After the fingerprint is collected, it is brought to a trained examiner for testing. The examiner carefully picks out any distinguishing characteristics from the print itself to run it through a collective database system like Federal Bureau of Investigation’s Integrated Automated Fingerprint Identification System (IAFIS).
After manually comparing database match results to make an exact match, the examiner will either make a positive identification, or if the results are inconclusive, the process will have to be repeated and often a new set of fingerprints will need to be collected. Once the results are final and accurate, the findings can be used in court to place a suspect/victim at the scene of a crime.
Noncriminal Uses
But not every fingerprint is used for something as serious as a criminal investigation. Nowadays technology allows us to use fingerprints for all kinds of verification efforts. From logging into a locked phone, to making an online payment, we use the unique features of our forefingers to quickly verify our identity, constantly. This identifier that was once only employed in a criminal investigation is now a common and efficient way to add security to daily tasks.
Medicine
DNA fingerprinting in medicine is incredibly useful. It can identify a donor for transplant or even design personalized treatment for a patient. And on a smaller scale, fingerprinting can easily identify that the sample the lab receives has been accurately labeled.
Genetically Modified Foods
Because all living things contain DNA, it only makes sense that scientists have found a way to use this to benefit the greater population. Agricultural scientists will employ the use of fingerprinting in everything from creating plant hybrids to ensuring the pedigree of a pet. The effects of genetic verification impact us every single day whether we realize it or not.
The Future of Fingerprints
Once strictly considered a helpful tool in criminal investigations, fingerprints now represent convenience and ease of use for the individual. From creating stronger crops to settling paternity suits, genetic markers like fingerprints are changing the way we eat, receive medical care, determine innocence and more. Technology is still only scratching the surface of the capabilities of this complex genetic tool.