CASE CLOSED
CONTENT WARNING: This article contains references to rape, sexual violence and murder. Reader discretion is advised.
The “Golden State Killer,” who was responsible for at least 13 murders and 45 rapes throughout California in the 1970s and 1980s, eluded law enforcement for decades. But in 2017, investigators tried to reopen the case. They extracted the suspect’s DNA profile from a rape kit and uploaded it to GEDmatch <www.gedmatch.com>, which pools results from various genealogy DNA tests.
DNA matches to the kit led investigators to possible relatives of the suspect. Using genealogy research, they built out a family tree, then looked for suspects who had the right DNA profile. Two months later, they had a shortlist of names. And in April 2018, police arrested Joseph DeAngelo, who would plead guilty to multiple counts of rape and murder, and be sentenced to life in prison. In just a few months, DNA was able to solve cases that had stumped law enforcement for nearly 50 years.
The powerful methodology used in the Golden State Killer case has evolved into a new field: investigative genetic genealogy (IGG). The FBI reports more than 250,000 murders have gone unsolved since the 1960s, with another 6,000 added every year. IGG is helping to solve that backlog by combining genetic analysis with genealogical research.
But what does it mean for DNA test takers and their relatives? Read on to learn about investigative genetic genealogy: how it works, what major companies are doing in response, and why it’s sparking some controversy in the genealogical community.
