A suspect believed to be the notorious Golden State Killer –  wanted in a dozen murders and nearly 50 rapes from the late 1970s to the mid-1980s – was reportedly arrested in California on Wednesday.

Joseph James DeAngelo, 72, was arrested at his Citrus Heights home, 16 miles northeast of Sacramento, on two counts of murder, a law-enforcement source told FOX40. He is reportedly on suicide watch and being held at the Sacramento County jail.

Shelly Orio, a spokeswoman for the Sacramento County District Attorney’s Office, told The New York Times a “major development had been made in the case.”

Police said they hope to release more information at a 12 p.m. PDT press conference Wednesday at the District Attorney Crime Lab in Sacramento, according to the Sacramento Bee.

The Golden State Killer is believed to be responsible for at least 12 murders, 45 rapes and 120 home burglaries throughout Sacramento County, according to FOX40. The cold-case killer is believed to have raped 37 people around Sacramento and Central Valley and killed two between 1976 and 1978, according to the Bee. Officials believed he moved to the Bay Area and Southern California from there.

“It is the most prolific unsolved serial killing case probably in modern history,” Sacramento County District Attorney Anne Marie Schubert told FOX40.

Jane Carson-Sandler, who is believed to have been raped by the Golden State Killer, also known as the East Area Rapist, told South Carolina’s The Island Packet on Wednesday she was contacted by authorities about his possible arrest. “I just found out this morning,” she told the newspaper. “I’m overwhelmed with joy. I’ve been crying, sobbing.”

Interest in the cold case was renewed following the release of the late author Michelle McNamara’s crime novel, I’ll Be Gone In The Dark.

McNamara’s widower, actor Patton Oswalt, and her friend Billy Jensen published the book after her death. It reached No. 1 on The New York Times’ bestseller list last month, according to the Bee.

Oswalt wrote in a tweet he hoped to ask the Golden State Killer questions McNamara had wanted answered before her death.