Thanks to shows like CSI and Law and Order, the general public’s knowledge of forensic science has never been greater, but unfortunately, the truth doesn’t always make for good television. And while DNA can be a useful investigative tool in real life, it is nowhere near perfect the way it appears to be in detective shows. San Marcos criminal lawyers believe the concept of DNA transferring is a perfect example of why a DNA sample should never serve as the only evidence in a case.
The Imperfections of Forensic Science
We’ve previously talked about some of the biggest myths associated with forensic science, including the #1 myth: Forensic science is foolproof. In fact, while DNA is one of the most reliable forms of forensic science, it still has many errors –some of which scientists are still learning about. A case in Silicon Valley recently provided scientists with a real life example of DNA transference –something that up until that point was only theoretical.
What is DNA Transference?
DNA doesn’t just come from your hair, nail clippings and body fluids. Every cell of your body carries DNA, which means that as you shed skin cells, you’re also shedding DNA. That means that anything you touch could end up with your DNA on it. The concept of DNA transference involves some of that abandoned DNA moving from one surface to another surface without the person who provided the DNA sample ever touching the second surface.
Researchers first tested the theory by asking volunteers to share a jug of juice at a table, without ever touching each other or each other’s glasses. After only 20 minutes, samples were taken of the volunteer’s hands. Even though participants never touched one another, 50% of them were found to have someone else’s DNA on their hands.
What Does This Mean for a Fallbrook Defense Attorney?
It means that just because DNA is found somewhere or on someone, it doesn’t mean that person is guilty of a crime. In the previously mentioned case in Silicon Valley, a murdered man was found to have another man’s DNA under his fingernails. Fortunately, the police dug deeper and found the DNA was only there due to transference from a pulse oximeter device in the ambulance the dead man used after the suspect.
This case as well as studies on the subject can provide a new avenue of defense arguments in cases where the only evidence is a DNA sample. Police can even contaminate a DNA sample through improper collection and storage techniques.
The concept isn’t limited to murder cases either. A 2016 study in Canada found that a father’s DNA will often be found on his daughter’s clean underwear if their clothes are washed together and sometimes a fragment of sperm might even survive the wash. While no reasonable sexual assault defense attorney in Escondido would argue DNA transference if sperm are found in a woman’s vagina after a rape, he may be able to argue it if the only DNA evidence is found on the woman’s underwear and she and the suspect share a washer.
Obviously DNA transference isn’t something that will affect most criminal cases in North County, but if you are facing charges and the only crime is DNA evidence, it might be a strategy for you and your Rancho Bernardo criminal lawyer to discuss. If you have any questions about this or any other legal defense strategy, please call (760) 643-4050 to discuss your case with Peter M. Liss.
Creative Commons Image by CJ Sorg