Organizations

Exeter Police Department

Law enforcement

The Exeter Police Department in Tulare County employed Joseph DeAngelo as a police officer from 1973 to 1976. During this period, the nearby city of Visalia was terrorized by a prolific burglar known as the Visalia Ransacker, who committed over 100 burglaries. DeAngelo is believed to have been the Visalia Ransacker, committing his earliest known crimes while serving as a sworn officer. He transferred to the Auburn Police Department in 1976.

Federal Bureau of Investigation (FBI)

Law enforcement

The FBI provided critical support to the Golden State Killer investigation, particularly in the final phase that led to DeAngelo's identification. The FBI lab analyzed DNA evidence and the bureau's resources supported the forensic genealogy effort. The case became a landmark example of federal-local law enforcement cooperation on cold cases and influenced the FBI's adoption of forensic genealogy as an investigative tool.

GEDmatch

Technology

GEDmatch is a free, publicly accessible genetic genealogy database where users voluntarily upload their DNA profiles to find relatives. Investigators uploaded the Golden State Killer's crime scene DNA to GEDmatch, finding partial matches to distant relatives of DeAngelo, which allowed genetic genealogist Barbara Rae-Venter to build family trees leading to the suspect. The case sparked a major privacy debate about law enforcement access to consumer DNA databases. GEDmatch subsequently changed its terms of service to require users to opt in to law enforcement searches.

Parabon NanoLabs

Technology

Parabon NanoLabs is a DNA technology company based in Reston, Virginia, that has become one of the leading providers of investigative genetic genealogy (IGG) services to law enforcement. While Parabon was not directly involved in the initial Golden State Killer identification, the case catalyzed their expansion of forensic genealogy services. Parabon's Snapshot DNA phenotyping and genetic genealogy services have since been used to solve hundreds of cold cases across the country, making them a central player in the forensic genealogy revolution that the GSK case ignited.

Sacramento County Sheriff's Department

Law enforcement

The Sacramento County Sheriff's Department was the primary law enforcement agency investigating the East Area Rapist attacks in Sacramento County from 1976 to 1979. The department handled dozens of rape cases attributed to the EAR and coordinated with other agencies as the crime spree expanded. After DNA linked the EAR to the Original Night Stalker murders in 2001, Sacramento remained a central hub for the investigation. The department collaborated with the FBI and district attorney's office on the forensic genealogy effort that identified DeAngelo.