Have you sent your spit to one of the genetic-testing companies? It can be interesting to find out our DNA ancestry and perhaps proactive to learn if you might be genetically predisposed to certain health risks. And the police are interested in your DNA profile too.

In the 1970’s and 80’s, a person dubbed the “Golden State Killer” murdered12 individuals and raped45 women throughout California, including in Orange County. Police knew it was one person who committed these crimes because they had collected the DNA of the suspect in each of these cases. But they couldn’t find a match for the DNA. While the FBI and state law enforcement agencies have routinely collected DNA from arrestees and/or individuals convicted of crimes, the Golden State Killer’s DNA was not in any DNA data bank.

Earlier this year, police found their man. Now 72 years old and a former police officer (who committed some of the crimes while still working as an officer), the suspected Golden State Killer was arrested this spring.

So, what does this have to do with the genetic testing companies that offer genetic profiles to consumers who provide a salvia sample? The path that led to the identity of the Golden State Killer started with a relative of the killer. When consumers have their DNA analyzed, the companies have that information in their databank. There are also free services that consumers can use to research their ancestry through their DNA profile provided by the genetic testing companies. The Golden State Killer happened to have a distant relative who had availed him or herself of one of the online and public DNA and genealogy research tools.

By investigating the various DNA and ancestry sites, police were able to find a match to the unknown killer that narrowed their search down to one family tree.  Once the police were able to narrow the search, they were able to hone in on possible suspects that matched the age range, old composite sketches, and known whereabouts of the killer. After several false starts, law enforcement identified a person they believed to be the suspect. He was surveilled where police observed him touching items from which they collected DNA samples (unbeknownst to the suspect at the time). The DNA proved to be a match and the Golden State Killer was finally arrested over 40 years after he began his crime spree.

While identifying the Golden State Killer is a good thing, there is a looming privacy issue in law enforcement’s use of DNA databanks. These databanks, in a sense, turn every consumer who makes use of them into a potential informant. Consumers who provide their DNA for testing aren’t just providing information about their DNA, but also DNA information about all their relatives, even very distant relatives that the consumer doesn’t know.

The largest consumer genetic and ancestry testing companies say they will not provide DNA evidence to law enforcement without a warrant or subpoena. That may not mean a lot because as in the case of the Golden State Killer, his distant relative uploaded his or her genetic profile on a public website.

The problem is that sometimes DNA profiling using the DNA of a relative can (and has) render false positives. In fact, in the Golden State Killer case, the police identified at least one wrong target, putting that innocent individual under suspicion. A couple of state have banned the use of familial DNA searches because it places many innocent people under suspicion.  But familial DNA investigation is, without a doubt, a break-through crime fighting tool that law enforcement is not going to give up. Weighing privacy concerns and false-positive identifications against the effectiveness of this tool will certainly be an issue in the years to come.

Orange County criminal defense attorney, William Weinberg offers effective advocacy to those accused of a crime. He is available for a free consultation to discuss your criminal matter. He can be reached at his Irvine office at 949-474-8008 or by emailing him at