How was the Golden State Killer tracked down?

Police Used genealogy websites to compare DNA samples!

The Golden State Killer is arrested after four decades. With a criminal activity ranging from burglaries, rapes and murders in the 70’s and 80’s, then a full stop, it looked like the Golden State Killer managed to elude investigators for ever, as the Zodiac killer did. But perseverance, forensic technologies and new investigative methods brought his identity to light, for all of us to see who the monster behind all those crimes was.

His name? Joseph James DeAngelo. A former police officer, fired from his job for shoplifting dog repellent and a hammer.

More than four decades have passed until investigators finally made an arrest.

You can find a more extensive post about Golden State Killer here: The Golden State Killer – Serial Killer

But how did they get to him? How did they manage, after all this time, to finally bring his name to surface?

What investigators did, was to use online genealogical websites. Why those? Because genealogical websites contain genetic information from people who wish to find more information about their family background and history.

DNA samples from one of the crimes scenes was used to be compared with samples from those websites. It was a long process over a long period of time, time which was used by crime labs to explore online family trees that seemed to match DNA samples from the East Area Rapist’s crimes. THen, after identifying samples, investigators followed up with individuals in those families to see if they could be potential suspects.

Then, a match was discovered. On April 19, 2018, Sacramento District Attorney Anne Marie Schubert received a call with news that triggered a rush of excitement among Sacramento investigators and set the investigation into high gear.


The Call

“I was at a dinner at Cristo Rey High School and Steve Grippi called me,” she said. “And so I probably used a few words I wouldn’t put in a newspaper, but basically said, ‘You’d better not be lying to me.'”

District Attorney Anne Marie Schubert

District Attorney Anne Marie Schubert

The match was Joseph James DeAngelo. A 72 years old retiree and former police officer. He was still living in the area on a street in Citrus Heights. Detectives set up surveillance on him, follwing up with his daily routines. Schubert had a genetic match, but she wanted to be sure that what they have is a clear proof. So she ordered more probes to be collected.

During surveillance, two more separate DNA samples were collected from items he discarded )which means police probably went through his trash).

“The second sample was astronomical evidence that it was him,” Schubert said, adding, “There were a whole lot of holy s— moments.” 

Authorities began moving quickly to plan the arrest.


Golden State Killer Is Arrested

On Tuesday afternoon, FBI agents and detectives took DeAngelo into custody when he stepped outside his home.

Sheriff Scott Jones

Sheriff Scott Jones

“He was very surprised,” Sacramento Sheriff Scott Jones said Wednesday at a news conference just outside the Sacramento District Attorney’s Crime Lab. “It looked as though he might have been searching his mind to execute a particular plan he may have had in mind…..He was not given the opportunity. It happened almost instantaneously and he was taken into custody without any incident at all.”

Golden State Killer arrest

Authorities gather outside the home of suspect Joseph James DeAngelo on Wednesday. (Rich Pedroncelli/Associated Press)

Joseph James DeAngelo - Golden State Killer Is Arrested

PHOTO: Joseph James Deangelo, known as ‘The Golden State Killer,’ is seen in this police booking photo, April 25, 2018, after being apprehended. (Sacramento Police Department)



Joseph James DeAngelo is expected to face charges in 12 homicide cases in Sacramento, Orange, Santa Barbara and Ventura counties, stretched from 1974 through May 1986.

DeAngelo faces arraignment in Sacramento Superior Court on Friday. At the time when some his murders were committed, the death penalty was deemed unconstitutional. Other crimes are eligible for death penalty. Prosecution has to determine if he will face death penalty charges.


Michelle McNamara and her book: “I’ll Be Gone In The Dark”

Michelle McNamara has passed away in 2016, before finishing the book. She became obsessed with the Golden State Killer “There’s a scream lodged permanently in my throat now,”. 

At the time of her death she had amassed 3,500 files related to the case, plus dozens of notebooks, legal pads, digitized police reports and 37 boxes from an Orange County prosecutor (the book was finished by her lead researcher and a colleague).

I'll Be Gone In The Dark

Michelle McNamara “I’ll Be Gone In The Dark” book cover

After the arrest broke the news, Her husband, Patton Oswalt, said: “You did it Michelle”, praising her work on investigating the crimes.


We will make updates as soon as more information is released.