The Victims Left Behind by Genetic Genealogy
The victims of the so-called Golden State Killer lived in subdivisions and middle-class neighborhoods. They included a nurse, a medical student, a bank loan officer, and a lawyer shortlisted for a county-court judgeship. Investigators puzzled over these cold cases for more than 30 years. Then, in April 2018, their efforts finally paid off when they identified a suspect, a 72-year-old former police officer, as the Golden State Killer using a powerful new technique called genetic genealogy.
This past August that man, Joseph DeAngelo, was sentenced to life in prison after pleading guilty to 13 counts of murder. But the influence of this one case has spread much wider, creating a new tool for criminal investigation. Very quickly, police around the country began embracing genetic genealogy, which uses online consumer databases to identify suspects through family connections. Investigators can upload crime-scene DNA to these sites and then build out large family trees to look for potential suspects.
Within months, genealogists using these databases had helped law enforcement solve a burst of cold cases, many of them rapes and murders dating back to the 1970s and ’80s. These first cases, as with the Golden State Killer case, tended to be notorious crimes—ones that received widespread coverage, had evidence preserved, and centered on victims with families who continued to press for justice. They were just the
