The average juror these days tends to believe that forensic science is far more reliable than it is. This is actually due to a phenomenon known as the “CSI Effect,” wherein pop culture crime shows have influenced the public to believe that fingerprints, DNA, blood splatter and other forms of forensic evidence are indisputable. But the reality is that all forensic specialties have their problems and many, like blood splatter, are downright questionable. Even the oldest and most widely trusted of these techniques has some issues, but a new technique means that one of the major problems when it comes to the accuracy of fingerprint analysis can now be eliminated.
Problems with the Accuracy of Fingerprint Analysis
Many people are surprised to hear that criminal lawyers often challenge the accuracy of fingerprint analysis results. But that’s because this forensic technique still has many issues. For one thing, a fingerprint at a crime scene could have been left as much as a week before the crime took place as long as it was not damaged by dust or someone touching it. When it comes to a fingerprint on an object, the matter is even more problematic as someone could have touched an object that was purchased or given to the victim, even if the person who left the fingerprint had never met the victim in his life.
Beyond that, the accuracy of fingerprint analysis itself is not guaranteed because differences in different fingerprints can be so minuscule. In fact, a 2006 study showed that when six professional fingerprint analysts were asked to review prints they had already analyzed, only two reached the same conclusion they did the first time they evaluated the prints.
A well known case of mistaken fingerprint identity was the Portland lawyer accused of having his fingerprints on the materials for the Madrid train bombings. It turns out they only had partial prints and they weren’t his but he spent months in jail before being exonerated.
Changes to Fingerprint Analysis Accuracy
While the problems with identifying who left the fingerprints remains and fingerprints on objects could still be left by a shopper who looked at the product before the victim brought it home, a new technology is making it so detectives can tell if a print was left within 24 hours of the time it was discovered. Researchers have found that certain oils in a person’s skin breakdown within 24 hours after being left in a fingerprint and now detectives can identify if these oils are still present.
What This Discovery Means
To start with, this won’t affect all cases, but only those where the crime scene is discovered and the fingerprints analyzed within 24 hours of the time of the crime. When this is the case, a fingerprint that was left within that time frame may indicate that a suspect was at the crime scene at the time of the crime -though it’s still not a guarantee. There are still many valid reasons a person’s fingerprint could be there within 24 hours of the time of the crime, such as delivering food, having an innocent conversation with the victim, etc., but this does help close in a list of suspects and if someone lies about not being there, it will make them seem more suspicious.
It’s worth noting that this innovation won’t just help the prosecution. If a print shows you were at the crime scene, but not during the 24 hours before the time of the incident, your defense attorney may use this to your benefit. Of course, just because someone was at a crime scene outside of the 24 hour window doesn’t mean she is innocent either -this could also be used as proof that the suspect knew the victim and even that she scoped out the crime scene beforehand. This is why it’s so important to not say anything until your attorney is present.
If you have been accused of a crime, remember that forensics can help or hurt you, but that it is not an exact science either. When you’re suspected of a crime or have been arrested, call Peter M. Liss at (760) 643-4050 to schedule a free initial consultation.
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