If you’re like me and love a good murder-mystery show, you know that fingerprints are like the holy grail in murder investigations. Once forensics finds a clean set of prints, the mystery is solved and the culprit caught. But, how exactly does fingerprint analysis work, and is it as reliable as they say?
Fingerprinting was actually developed by a number of people. One of the earliest scientists to notice the unique patterns was J. C. A. Mayer. In 1788, he declared that fingerprints were so distinctive, no two people shared a design.
Henry Faulds, one of the first scientists to explore the curiosity revolving human fingerprints, brought the art to the public eye. Like Mayer, Faulds noticed the unique patterns that define fingerprints. Faulds worked as a missionary in Japan in the 1870’s, according to Smithsonian Magazine. There, he looked through ancient pottery and noticed that a fingerprint was still visible. Inspired, he took the fingerprints of his colleagues at the hospital, and kept a record of them. One day, the staff noticed that someone stole alcohol from storage. Faulds was able to compare the fingerprints on the bottle to the fingerprints on record and caught the person responsible. Shocked, Faulds wrote a letter explaining that the police can use fingerprints to identify possible suspects.
To test the dependability of fingerprint science, Faulds and his team scraped the skin off their fingertips. Over time, the skin grew back in the exact pattern as before. Therefore, fingerprints were not only unique per person, but could not be changed.
Although Mayer was on the right track when he recognized the unique pattern of human fingerprints, his statement was not necessarily correct. While scientists have not disproven the idea of fingerprint individuality, they also haven’t proven it to be true. Doubt comes from the initial science behind fingerprint analysis. Which factors are supposed to be compared, and how many should be compared before a match is determined?
Also, many fingerprints taken from crime scenes are incomplete, making them virtually useless. Then, there are mistakes that send the wrong people to jail. According to a statement from the American Association for the Advancement of Science (AAAS) in 2017, fingerprints are no longer reliable in court cases.
The 160-page report goes into detail the various reasons fingerprint analysis could be unreliable. The biggest argument, however, is that misidentification is a huge problem. Authorities have convicted too many people for crimes they didn’t do.
“We have concluded that latent print examiners should avoid claiming that they can associate a latent print with a single source and should particularly avoid claiming or implying that they can do so infallibly, with 100% accuracy,” the AAAS states.
The report also argues that fingerprints are not fact. Rather than declare findings from fingerprint analysis fact, authorities should use it as a basis for investigation. In short, it seems the argument revolves around terminology. Rather than saying the fingerprints can “identify” a person, they should be “practically certain of” the person whose prints were taken.
While fingerprint analysis has made a profound impact on the criminal justice system (and pop culture), it seems that there are better ways to “identify” the culprits of various incidents. Fingerprinting should not be an end; it should be a beginning. The AAAS has made it clear that there is no scientific basis for the accuracy of fingerprint analysis. Although fingerprinting has made the jobs of law enforcement easier by narrowing down the pool of potential suspects, it is not a reliable source for forensic identification.