Golden State killer Joseph DeAngelo says he is 'truly sorry' as he is jailed for life without parole

Former police officer confessed to 13 murders and multiple rapes and burglaries

The so-called Golden State Killer told a court in California that he was "truly sorry" for his actions as he was sentenced to life in prison without parole.

Joseph DeAngelo, 74, the former police officer who came to be known as the Golden State Killer, had admitted 13 counts of first-degree murder and multiple rapes and burglaries after pleading guilty in a deal that kept him from receiving the death penalty.

He will be required to register as a sex offender and pay restitution to the victims or their family members, as well as any fees and fines associated with the trial.

He told victims and the family members of victims that he was "truly sorry" prior to his sentencing.

"I listened to all your statements, each one of them, and I'm truly sorry for everyone I've hurt," he said.

DeAngelo also admitted he committed dozens of other sexual assaults that could not be prosecuted due to statute of limitation restrictions.

Most of his crimes took place during the 1970's and 1980's in California. Prosecutors said he admitted harming 87 people in 53 crimes.

The Associated Press reported that there were so many victims of DeAngelo's crimes present for his sentencing that Sacramento County Superior Court Judge Michael Bowman had to issue his ruling in a university ballroom to allow space for everyone to attend.

The crime spree began in 1975 while he was working as a police officer in Exeter, California. DeAngelo began by stalking his victims, but eventually moved on to sexual assaults, rapes and murders.

Orange County District Attorney Todd Spitzer said that while he is pleased with the outcome, he believes DeAngelo deserves to die for his crimes.

"I honestly believe that this person – not even a person, this beast – deserved the ultimate punishment of death. But we met with our victims, We knew the age of the case. We knew how long it took to solve. And we knew that this was the right thing to do," he said.

DeAngelo's crime spree is a central element of the HBO Documentary series I'll Be Gone in the Dark, which documents the life of late true crime writer Michelle McNamara and the production of her book of the same name.

Ms McNamara became obsessed with the case and worked tirelessly to discover the identity of the Golden State Killer – referred to as the East Area Rapist in the early episodes of the show – and get justice for his victims.

The author died in 2016, two years prior to DeAngelo's arrest. Breakthroughs in DNA tracking provided authorities with the evidence they needed to arrest him.