WELD COUNTY, Colo. — A Colorado father has pleaded guilty to killing his two young daughters and his pregnant wife in a deal that removes the death penalty as a possible sentence, according to the Weld County District Attorney's Office.

Christopher Watts reached the plea deal Tuesday afternoon, CBS Denver reports. Investigators said Watts in August killed his 34-year-old wife, Shanann, and daughters Bella, 4, and Celeste, 3, before dumping their bodies on property belonging to an oil company where he worked.

The girls' bodies were found in oil barrels and Shanann's body was found in a shallow grave nearby. Shanann Watts was 15 weeks pregnant with a baby boy she planned to name Nico.

Christopher Watts is in court for his arraignment hearing at the Weld County Courthouse on August 21, 2018 in Greeley, Colorado. RJ Sangosti/Getty

The case gained national attention in part due to Christopher Watts' public pleas for his family's return before his arrest.

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Watts appeared in court Tuesday and pleaded guilty to all nine counts against him, including five counts of first-degree murder, one count of unlawful termination of a pregnancy, and three counts of tampering with a deceased human body. Watts wept as he entered the pleas, the Denver Channel reported.

The plea deal calls for Watts to be sentenced to three consecutive life sentences for the deaths of Shanann, Celeste and Bella, along with additional time for the unlawful termination of the couple's unborn child, Weld County District Attorney Michael Rourke said at a press conference following the hearing. He said a judge has not formally accepted the guilty pleas or the sentence. Watts is scheduled to be sentenced Nov. 19.

Rourke said he had detailed conversations with Shanann Watts' family after Christopher Watts' attorney approached him about a possible deal. He said the family was strongly against pursuing the death penalty, especially after they discussed the extensive delays in the process in Colorado. Rourke said their wishes were the most compelling factor for him in reaching the plea agreement.

Rourke said Shanann Watts' mother told him, "'He made the choice to take those lives, I do not want to be in the position of making the choice to take his.'"

"That about as firmly as she could have said it to me," Rourke said.

Rourke said he hoped the agreement would bring some measure of closure for the family, who were present during the court hearing and the press conference. But he said: "I know that will never be fully realized, because the tragedy that sits before us today is the loss of four beautiful lives. And no matter what happens today, no matter what happens at a sentencing hearing down the road, we can't get them back."

Shanann Watts and her two daughters, Bella and Celeste CBS Denver

Rourke said his office discussed whether to require Watts to provide a full and accurate account of what happened during the slayings, but said everyone involved agreed Watts would never offer a truthful statement. Watts has claimed Shanann had killed one daughter and was actively trying to kill the other when he attacked her in an act of passion, CBS Denver reported.

Rourke said "the spotlight he tried to shine on Shanann, falsely, incorrectly and frankly, a flat-out lie, has been corrected" by his guilty pleas. "The spotlight shines directly where it belongs — on him," Rourke said.

Rourke said investigators believe they have a partial motive for the slayings, but said he wouldn't give details until after Watts is sentenced.