June 1 (UPI) -- Investigators in California obtained the DNA of suspected Golden State Killer Joseph James DeAngelo by swabbing his car door and taking a used tissue from his trash, according to court documents a judge approved for release Friday.
Sacramento County sheriff's officials arrested DeAngelo on April 25 more than 40 years after the start of a decade-long rape and killing spree they believe he's responsible for. He faces 12 counts of murder in Orange, Sacramento, Santa Barbara and Ventura counties.
The Golden State Killer -- also known as the East Area Rapist, Original Night Stalker and the Diamond Knot Killer -- is believed to be responsible for at least 12 killings and 45 rapes between 1976 and 1986 in the Sacramento, Central Valley and Southern California region. The court released 123 pages of redacted documents including details of the cases, evidence and the arrest report. Nine pages alone detail personal items the suspect took from his victims in dozens of crimes.
At the time of his arrest, investigators said they traced the killings to DeAngelo through a familial DNA connection on a genealogical website.
Investigators submitted DNA evidence collected from the crimes to a genealogical website, hoping to connect to the suspect. A distant relative to DeAngelo submitted their evidence to the site, and through some digging, detectives narrowed down their search to the Citrus Heights man.
They surveilled DeAngelo's house in April for three days, collecting evidence from a trash can he set in the street for collection. They also followed him to a parking lot at a retail store in Roseville.
"A swab was collected from the door handle while DeAngelo was inside the store," Detective Sgt. Ken Clark wrote in an affidavit. "This car door swab was submitted to the Sacramento [District Attorney's] crime lab for DNA testing."
Evidence from both collections matched with the DNA collected from the crimes.
The Golden State Killer case was the subject of I'll Be Gone in the Dark, an investigative true crime book written by the late Michelle McNamara and a podcast of the same name featuring interviews with McNamara, her husband Patton Oswalt and others who worked on the book.