In exchange for Chris Watts' guilty plea, the death penalty will not be considered, the Weld County District Attorney's office said.
He arrived the court wearing a bullet proof vest and sobbed each time he pleaded guilty to each of the nine charges.
After his pregnant wife and two daughters disappeared, Watts stood on his porch in Colorado and told reporters how much he missed them. According to The Associated Press, Shanann Watts' parents and brother were present in the hearing.
With the November 6 deal, Watts has agreed to five counts of murder in the first degree, one count of unlawful termination of pregnancy, and three counts of tampering with a deceased human body.
Watts is accused of killing his pregnant wife and their daughters at their home north of Denver. Police have said Watts drove their bodies to an oil site owned by his former employer.
Shanann was found in a shallow grave in a crude oil field where her husband worked.
Rourke spoke at a news conference following the hearing in Weld County District Court, flanked by law enforcement from the agencies involved in the case, including the FBI, Colorado Bureau of Investigation and Frederick Police Department.
He had previously claimed that after telling his wife he was having an affair, she had killed one of their children and was trying to kill another when he attacked her. If it goes as planned, Rourke said he will not fight the release of the autopsy reports for Shanann Watts and her daughters.
"That, to me, was the most important consideration in deciding how to proceed with this case", Mr Rourke said.
Killer dad Chris Watts has pleaded guilty to murdering his entire family in a bid to save himself from the death penalty, RadarOnline can confirm.
While Rourke denied the initial plea offers, he accepted one made a few days ago that did not dismiss any of the nine charges Watts faces.
'I don't know how I could have sat in Sandy's kitchen and asked her to commit the next 25 years of her life to the criminal justice system without any assurance that the sentence would ever actually be imposed, ' he said. He gave no details about that talk, only saying, "I just want them back". Rourke said he was "sick" and "saddened' over the case".
Investigators never believed his story, Mr Rourke said.
Image: Shanann and Christopher Watts.
But in his guilty plea, Watts made it clear that he, and not his wife, had killed the girls.