How Genetic Genealogy Caught America’s Most Elusive Killer

For over a decade, a shadowy predator stalked California, leaving behind a trail of violence that included fifty rapes, twelve murders, and over one hundred burglaries between 1974 and 1986. Known by different names throughout his crime spree - first as the Visalia Ransacker, then the East Area Rapist, and finally as the Original Night Stalker - this elusive criminal avoided capture for forty years, cementing his place as one of America's most infamous unsolved serial cases. The case's resolution in 2018 marked a watershed moment in forensic science, demonstrating how revolutionary DNA technology and public genealogy databases could finally crack even the coldest cases.

The Evolution of a Serial Predator

The Golden State Killer's crimes evolved in both brutality and geographic range over time. His criminal career began in Visalia, California between 1974 and 1975, where he operated as a burglar who broke into homes to steal trinkets, jewelry, and cash. What set him apart was his bizarre behavior - he would rearrange household items, stack dishes on bound victims, and leave personal belongings in strange places. Initially dismissed as a petty thief, his intrusions grew increasingly brazen, culminating in the murder of journalism professor Claude Snelling during an attempted abduction of his daughter.

Escalation to Sexual Violence

After relocating to Sacramento, the offender escalated to sexual violence between 1976 and 1979, developing a signature method that involved targeting couples, tying up the man and piling dishes on his back as a warning system while he assaulted the female victim in another room. He would linger in homes for hours, sometimes eating food, stealing souvenirs, and later taunting victims with phone calls. Despite an unprecedented manhunt, he suddenly vanished in 1979, only to reappear in Southern California with even deadlier intentions as the Original Night Stalker from 1979 to 1986.

The Murderous Final Phase

As a full-fledged serial killer, he began murdering victims after assaults, bludgeoning couples to death in their homes and leaving cryptic messages like poems at crime scenes. He meticulously avoided leaving forensic evidence by always wearing gloves and masks to prevent DNA transfer. Then, in 1986, the attacks mysteriously stopped.

Decades of Frustration for Investigators

For decades afterward, detectives pursued thousands of leads without success, facing major obstacles including the complete absence of fingerprints or reliable eyewitnesses, the limitations of pre-DNA forensic technology where blood typing couldn't sufficiently narrow suspects, and the strong possibility that the killer's police training helped him study investigative techniques to evade capture. A significant breakthrough came in 2001 when DNA from crime scenes was uploaded to the FBI's CODIS database, but even with matching DNA across multiple crimes, no suspect emerged because the killer had no prior criminal record and no close relatives in the system.

The Genetic Genealogy Breakthrough

The case's true turning point arrived with the advent of direct-to-consumer DNA testing through companies like 23andMe and AncestryDNA, which analyze over 700,000 genetic markers compared to CODIS's limited 20-marker system. Investigators turned to GEDmatch, a public genealogy database where they uploaded the killer's DNA profile and identified distant relatives - third cousins sharing about 1% of DNA. Through painstaking work building family trees using census records, obituaries, and newspaper archives, they narrowed the pool to Joseph James DeAngelo, a 72-year-old former police officer living near Sacramento.

The Arrest That Made History

To confirm their suspicions, police collected discarded DNA from his car door and a discarded tissue, matching it to crime scene evidence with absolute certainty. On April 24, 2018, DeAngelo was arrested, finally closing the longest-running serial killer investigation in U.S. history.

The Ripple Effect on Cold Cases

DeAngelo's capture triggered a forensic revolution, leading to the solving of over seventy cold cases through genetic genealogy, including high-profile cases like the Bear Brook Murders and Grim Sleeper case. It also established new protocols for law enforcement use of genealogy databases.