In April 2018, a remarkable event occurred that forever impacted criminal investigations. The Golden State Killer was finally arrested. And, more interestingly, was the method law enforcement used to finally identify the man who murdered 13, raped 50, and terrorized a whole state for nearly three decades. For the first time, law enforcement uploaded a DNA sample recovered from the crime scenes to a public consumer genealogy website, tracing the DNA to the perpetrator through comparison with distant genetic relatives who uploaded their own DNA, not for the purposes of catching criminals, but for simply tracing their family lineage.

The Golden State Killer case was considered the first to use forensic genetic genealogy, a method that has since been used in some 545 cases as of Dec. 31, 2022. It has been used to close cold cases like the Golden State Killer, to rapidly solve current cases like identifying the murderer of four Idaho college students in November 2022, as well as to finally name unidentified remains. Some genetic genealogy sites like AncestryDNA and 23andMe prohibit law enforcement investigations using an ordinary user profile, while others like FamilyTreeDNA and GEDMatch are open about allowing law enforcement access to their databases, even without court approval or warrants. Parabon NanoLabs, one of the most notable companies that provides DNA services to law enforcement agencies, has made more than 265 positive identifications in criminal cases, while the DNA Doe Project, a California nonprofit volunteer organization, has identified more than 100 sets of remains.