I’ve said before that I don’t understand the home DNA testing craze. Why would I, a sane person, voluntarily hork the very thing that makes me me (or to put it another way, the most personal piece of personal data I have) into a tube and mail it off to a corporation that’s going to do lord knows what with it? To my mind, that’s an extremely dumb thing to do. A lot of companies can’t seem to handle something as simple as your email address correctly, so why would you trust them with this? It’s your fucking DNA! And you’re making it publicly available! On purpose! Yeah, maybe finding out things you already know about where your grandma came from sounds fun, but what happens after that? What if, for example, that profile you sent to the publicly accessible database fell into the hands of an insurance company that was looking for a way to deny you coverage or make you pay more for it? Or what if, guilty or not, you wound up entangled in a police investigation? Finding out that you’re 98 percent Eastern European but you might be Asian too because you ate a grain of rice one time doesn’t sound quite as worth it now, does it?
But even though I fully intend to do my part to avoid having any of that happen to me, it may not matter. If an idiot or three in my family decides to waste his money, I’m as good as identifiable. If you don’t believe me, just ask the Golden State Killer. Yes, this one guy deserved it. But that doesn’t mean that everyone else is going to or that any of this is ok.
Even though the killer left his DNA at multiple crime scenes, investigators couldn’t find him until they turned to a massive genealogical website called GEDmatch. Users can upload their genetic profiles to GEDmatch — and websites like it — to learn about their family trees and look for long-lost relatives.
Investigators discovered that they could also use GEDmatch to look for a killer. They uploaded a fake genetic profile using crime scene DNA and found matches, not of the killer himself, but of his relative. From there, they could hunt through the family tree to find a suspect who had been in the right place at the right time. This is called a long-range familial DNA search, and it raises all sorts of questions about ethics, consent, and just how far law enforcement can go in their pursuit of a killer.