@Nrdsb4 -
He discarded his DNA, yes, so the police had it legally, and it matched evidence from the crime scene, but he didn’t consent to have his DNA up on that genealogy site. That’s what I meant by his right of privacy, not the drinking straw or whatever he tossed out and the cops picked out of the garbage. If his relative hadn’t put their own DNA up on that site, the cops wouldn’t have gotten a match. I just don’t know that your relative has the right to, in essence, give up your DNA. I’d feel a lot more comfortable with this if he had uploaded his own DNA (though, in this day and age, if I were a serial killer or a rapist, I wouldn’t be spitting into a tube and sending it off in the mail).
That said, I am really glad they caught this guy and I hope that the method of tracking him holds up. It’s similar to the familial DNA method that was used to get that other California serial killer a year or so ago except that, in that case, the relative’s DNA was in the police database and not a public one.