For four decades police hunted for the Golden State Killer – but it was a distant relative’s seemingly small decision that finally led investigators to their man.
On Tuesday Joseph James DeAngelo Jr – the man police believe is responsible for 12 murders and 50 rapes between 1976 and 1986 – was arrested.
Now, California newspaper The Mercury News has reported that the breakthrough that led to the Sacramento man’s arrest were saliva samples on a genealogy website.
The potential arrest of a serial killer caught the world’s attention. Post continues.
Unbeknownst to DeAngelo, his third and fourth cousins had used genealogy website GEDmatch to try to map their family tree. The distant relatives had sent in saliva samples to a service such as 23andMe and Ancestry.com for DNA profiling, and had then shared that profile to GEDmatch to try to find relatives and trace their heritage.
This is important, because unlike Ancestry.com and 23andMe, GEDmatch’s database of 900,000 DNA files is free and accessible to the public. For this reason, police do not require a court order to access this data.
Lead investigator Paul Holes used DNA collected from Golden State Killer’s crime scenes to search the database for a match, The Mercury News reports. When Holes was alerted to the partial DNA match with the cousins, detectives traced the family tree to find a man who would match descriptions of surviving victims.