Can Your DNA Link You to Crimes You Didn’t Commit?

You don’t have to be able to pronounce deoxyribonucleic acid to understand that our genetic fingerprint is embedded in our DNA and that we trail this telltale stuff behind us in traces of our skin, saliva, and sweat.

As such, with the rise of DNA technology, solving cold cases and linking suspects to airtight criminal convictions (or exonerations) has become a straightforward process. Right? Wrong.

Common Misconceptions About DNA Testing

Criminal defense attorney Kush Arora of Price Benowitz law firm in Rockville, Maryland, regularly faces this public misconception. “There’s an assumption much of the time,” he says, “whether it’s on the part of a judge or a jury, that if there’s DNA, that DNA must be correct. It can be frustrating.”

In other words, just because a DNA sample matches that of a particular suspect, it doesn’t mean the reason is because of that individual’s guilt. There are actually numerous aspects to the collection, processing, and analysis of a person’s DNA evidence that can raise questions about the certainty of such a conclusion.

“We’ve had cases thrown out for issues with DNA where there’s a match,” says Arora,” but the manner in which the evidence was collected or stored was faulty, or there’s an issue with the chain of custody—any number of things that could call into question the validity of the results.”

Your DNA Can Be at the Crime Scene Without You

In addition, a little-understood facet of DNA analysis has to do with how DNA can travel, landing on an object that the source never had contact with.

This type of DNA transfer was behind the so-called Phantom of Heilbronn, a suspected serial killer with a trail of more than 40 crimes throughout Germany, France, and Austria. The DNA trail led to a factory worker who produced the swabs used to collect police DNA samples. She was never at a crime scene herself, but she had contaminated the swabs before they ever left the factory.

Our DNA profile is everywhere. It travels with us and can be carried by others, such as healthcare providers and law enforcement officers. It was this last circumstance that nearly landed Lukis Anderson on death row for a Santa Clara County murder he didn’t commit. He had crime scene DNA under the fingernails of the victim.

Fortunately for Anderson, records from a nearby hospital gave him a documented alibi: He had been admitted when the crime occurred. The mystery of his itinerant DNA could best be understood by speculating that the same paramedics who had treated Anderson earlier that day had also responded to the 911 call at the murder scene.

Where DNA transfer is concerned, as with the Anderson case, much remains to be understood about how transfers occur and what impact this has on the conclusiveness of a DNA match at a crime scene. For now, it seems that confirmation bias can be a substantial hurdle for juries to overcome, as Arora attests.

If You’re Facing a Criminal Investigation, Get an Attorney

If you have privacy concerns about how law enforcement agencies or others may be using your DNA evidence or genetic material in the criminal justice system, contact an experienced criminal defense attorney to ensure the matter is properly handled. For more information on this area of law, see our overview of criminal defense.