Joseph DeAngelo, the former police officer believed to be the notorious "Golden State Killer," appeared in court on Monday and pleaded guilty to 26 charges.

The San Francisco Chronicle reports that DeAngelo was charged with 13 counts of murder and 13 counts of kidnapping for robbery in six different counties. He is set to be sentenced to life in prison without parole, with his guilty plea sparing him the death penalty. The 74-year-old appeared in court in a wheelchair to announce he had accepted the guilty plea.

A large number of victims and those related to victims appeared in court to see the guilty plea, and it is expected they will be able to address DeAngelo at the sentencing hearing in the near future. The identity of the Golden State Killer remained a mystery for decades, until two years ago investigators used a family genealogy website and were able to narrow down the suspects from there. He was arrested in April 2018 and charged with eight counts of first-degree murder with special circumstances. 

In the 1970s and '80s, DeAngelo is believed to have gone on multiple killing and raping sprees that provoked fear in thousands across the state of California. Often credited to a number of different nicknames throughout his life, including the Original Night Stalker and the Visalia Ransacker, DeAngelo supposedly killed at least 13 men and women over the course of 12 years.

Authorities have indicated that DeAngelo was also the perpetrator behind over 60 instances of rape, but the statute of limitations has expired on those crimes. It is suspected that he only stopped his crimes once he was no longer young enough to overpower his victims.