The DNA you send in the mail through genetics kits and ancestry programs like 23andMe and Ancestry can be used by police in a criminal investigation, but it doesn’t happen very often.
Recently, Joseph James DeAngelo, the man authorities suspect is the so-called Golden State Killer responsible for at least a dozen murders and 50 rapes in the 1970s and 80s, was arrested more than three decades after the last killing.
And according to the Sacramento County district attorney's office, investigators used information from an online genealogical site to determine whether the DNA from one of the crime scenes was a match, the Associated Press reported.