Content warning: This report contains details of murder and domestic violence that might be disturbing or harmful to some readers.

Christopher Watts told investigators in a new prison interview that he strangled his wife Shanann in bed, loaded her body into the backseat of his truck with their two daughters — who were still alive — and drove out to a Weld County oil site, where he smothered the girls to death.

The confession, made to investigators during a Feb. 18 interview at a Wisconsin prison and detailed in a report released Thursday by the Colorado Bureau of Investigation, is the first time Watts has confessed publicly to killing his daughters, Bella and Celeste.

Watts said he woke Shanann up the morning of Aug. 13 as he was getting ready for work because he wanted to talk. He straddled her on the bed while they discussed their marriage and future. Shanann confronted him about her suspicions that he was having an affair, which he denied. He told her that their marriage wasn’t going to last and that he didn’t love her.

Shanann told Watts that he would never see the kids again, he told investigators. Watts then strangled his pregnant wife.

Their 4-year-old daughter Bella walked in the room, holding her blanket, and asked what was wrong with her mom. Watts wrapped his wife in a sheet and dragged Shanann down the stairs and put her on the floorboard of his truck. Bella started to cry and her younger sister, Celeste, woke up.

He put the girls in the backseat of his truck and drove to the well site. He told investigators he thought about killing all of them — including himself — while he drove.

When they arrived, he took his wife’s body out of the truck. He then smothered Celeste, 3, in the backseat of the truck. He dumped her body in an oil tank while 4-year-old Bella watched. After watching what happened to her sister, Bella asked, “Is the same thing gonna happen to me as Cece?”

Watts then used a blanket to smother Bella, who fought back. He put her in a separate oil tank and buried Shanann nearby.

He told investigators that he doesn’t know what he was thinking at the time. He said he felt like “something else” was controlling him that day.

“This was like the epitome of being angry, the epitome of showing a rage, the epitome of losing your mind,” he said.

“I was absolutely sickened”

Six months ago, Watts stood on the front porch of his house in Frederick and told a local television reporter that he didn’t know where his pregnant wife and two young daughters had gone. They’d been reported missing on Aug. 13. He pleaded for them to come home.

Watts first admitted to killing Shanann to his father in a tearful conversation in a Frederick Police Department interview room. He said that he killed Shanann after witnessing her attempting to strangle Celeste and seeing Bella apparently dead on a baby monitor. He recounted the version of events to investigators shortly after.

In the Feb. 18 interview, Watts said he never thought to say that Shanann killed the girls until law enforcement introduced the idea to him during an interview.

A Weld County judge sentenced Watts to multiple life sentences in November for the murders of Shanann, Bella and Celeste. Watts previously pleaded guilty to the killings in exchange for an agreement that prosecutors would not seek the death penalty.

After the sentencing, Weld County District Attorney Michael Rourke said investigators still didn’t understand Watts’s motive for killing his family. Watts’s father, Ronnie Watts, also said at the sentencing that he didn’t understand why his son committed the crimes.

“I hope one day, Christopher, you can help us,” Ronnie Watts said that day.

Rourke said Thursday he had chosen not to read the report or listen to the audio of Watts’s confession, but had been briefed on it by investigators.

“When I got the briefing, it was the day after the interview was done, I was absolutely sickened, I was horrified,” he said.

He said that he and his office had thought of multiple scenarios of what could have happened during the case’s prosecution, but that this was so much worse.

“What boggles my mind and baffles me is why did he have to kill those little girls?” Rourke said. “Did he think they would rat him out? Did they become a nuisance? No words that come out of his mouth will ever answer that for me. I hope his life is miserable.”

“They said that they love you”

One of the attorneys representing Shanann’s parents, Greeley-based Steven Lambert, on Tuesday said he could not discuss the interview until next week because of an exclusivity agreement he signed with the “Dr. Phil” television show. The show aired interviews with Lambert and the family’s other attorneys Tuesday. Interviews with Shanann’s parents are expected to run next week.

Shanann’s parents told investigators that they don’t hate Watts, Frederick police detective Dave Baumhover said in the Feb. 18 interview.

“They said that they love you, they still love you,” Baumhover said. “And Sandy explained it: ‘He’s our son-in-law for eight years and we can’t just turn that off.’ So they don’t hate you.”

Watts told investigators that he feared for his life during his stay at the Weld County Jail and other Colorado correctional facilities. He said the other inmates at the Weld jail would yell at him from their cells, telling him to kill himself and threatening him. He was transferred to the Wisconsin facility shortly after his sentencing.

In the interview, he also denied having affairs or even knowing a man from Wyoming who said they had an affair and a woman from Colorado who claimed they once met in a Chik-Fil-A parking lot and had sex.

He did explain more details of his affair with a former co-worker, Nichol Kessinger. He said he wished they had never had a romantic relationship and that he never thought his marriage was bad before meeting her. He said that Kessinger knew he was married but that he lied to her and said he was pursuing a separation before he and Shanann had ever talked about it.

He said Kessinger would get upset about being “second fiddle” to Shanann, but never asked him to get rid of his family or play any part in their murders. He said they had not spoken since his arrest.

Watts said he regrets what he did. He keeps photos of Shanann, Bella and Celeste in his cell and “talks to them every morning and every night,” he told investigators. He has one of Celeste’s books in his cell.

Watts said he was ready to plead guilty to the crimes just weeks after his arrest. He told his defense attorneys the full story of what happened shortly after his arrest, he said.

He said he didn’t want to fight the charges because he didn’t want to extend the process or make his and Shanann’s families wade through the court process.

“I didn’t want them to go through this for two to four years,” he said. “I didn’t want my attorneys to lie for me for two to four years.”

Watts said he did not regret taking the deal, though he didn’t expect to be in prison for the rest of his life. He will not have the opportunity for parole.

Family and friends have described Shanann as ambitious and a “fireball” and said she loved being a mom. The girls were friendly and loved their parents. Photos posted of Bella and Celeste online by Shanann show the girls snuggling with their mom, making goofy faces at the camera and celebrating birthdays.

Shanann, Bella, Celeste and the couple’s unborn son — to be named Nico — were buried next to each other in North Carolina in September.

Content warning: This report contains details of murder and domestic violence that might be disturbing or harmful to some readers.