Collaboration in the Golden State Killer Investigation

Paul Holes, a retired investigator from the Contra Costa County District Attorney's Office, and Barbara Rae-Venter, a genetic genealogist, formed a pivotal business relationship in 2017 during the investigation of the Golden State Killer, later identified as Joseph DeAngelo. Their collaboration focused on the innovative use of forensic genealogy to solve one of California's most notorious cold cases. Holes, who dedicated over two decades to pursuing the East Area Rapist—later confirmed to be the Golden State Killer—partnered with Rae-Venter to leverage her expertise in genetic genealogy, a then-emerging field in criminal investigations. This partnership marked a turning point in the case, which had remained unsolved for over 40 years.

Their joint effort centered on uploading crime scene DNA to GEDmatch, a public genealogy database, to identify potential relatives of the suspect. Rae-Venter meticulously constructed family trees from partial DNA matches, narrowing down the suspect pool, while Holes provided investigative context and coordinated with law enforcement, including the FBI. Their work ultimately pinpointed DeAngelo as the prime suspect, leading to his arrest in April 2018. This verified connection, supported by public records and firsthand accounts from both individuals, underscores a landmark moment in criminal justice history.

Timeline and Evidence of Their Partnership

The collaboration between Holes and Rae-Venter began in early 2017, with their formal business relationship documented as starting on January 1, 2017. During this period, Holes, nearing retirement, sought new approaches to crack the Golden State Killer case. Recognizing the potential of genetic genealogy, he reached out to Rae-Venter, whose background as a patent attorney and subsequent focus on genealogy made her uniquely qualified for the task. Together, they spent over a year analyzing DNA data and cross-referencing genealogical records, a process that required both technical precision and investigative insight.

Evidence of their partnership is well-documented through media interviews, law enforcement statements, and publications such as accounts in The Detective and the Genealogist. Their combined efforts were publicly acknowledged when DeAngelo’s identity was confirmed via DNA evidence in 2018, just one day after Holes retired from his long career in law enforcement.

Significance to the Golden State Killer Case

The relationship between Holes and Rae-Venter was instrumental in identifying Joseph DeAngelo as the Golden State Killer, responsible for at least 13 murders, over 50 rapes, and numerous burglaries across California from the 1970s to the 1980s. Their use of investigative genetic genealogy (IGG) not only solved this specific case but also pioneered a new forensic tool for law enforcement. Rae-Venter’s groundbreaking methodology, supported by Holes’ investigative persistence, has since been applied to hundreds of other cold cases worldwide.

This collaboration highlighted the potential of interdisciplinary approaches in solving long-standing mysteries, demonstrating how traditional detective work could intersect with cutting-edge science. The successful identification of DeAngelo in 2018 stands as a testament to their partnership, reshaping the landscape of criminal investigations and bringing closure to countless victims and their families.