The broken father shook visibly as Chris Watts was charged with first-degree murder for his three family members.
Shanann Watts' father, Frank Rzucek Sr, shook visibly on Tuesday as District Judge Marcelo Kopcow read the charges against Christopher Watts.
Shanann's brother, Frank Rzucek Jr, rubbed his father's shoulders and glared unflinchingly at his brother-in-law. A bailiff stood between them.
Christopher Watts answered, "Yes, sir" when the judge asked whether he understood the murder and other charges against him and the penalties they carry, including the death penalty.
Watts is charged with first-degree murder in the deaths of his wife, Shanann, and four-year-old Bella and three-year-old Celeste.
Watts didn't enter a plea to three first-degree murder charges, two counts of killing a child under 12, one count of unlawful termination of a pregnancy and three counts of tampering with a deceased human body.
Shanann's body was buried in a shallow grave in an oilfield north of Denver and the girls' bodies were found submerged in nearby oil tanks, according to police arrest affidavit.
Watts told authorities his wife killed the children after he told her he wanted a separation. He said he erupted in rage after seeing her strangle one of the kids on a baby monitor and then strangled their mother inside the family's home, according to court documents.
Police first visited the home on August 13, after a friend asked officers to check on Shanann. She had missed a doctor's appointment and wasn't answering calls or text messages hours after returning home from a business trip, the friend said.
Police searched the house and found Shanann's cellphone stuffed inside a couch. Her purse was in the kitchen and a suitcase was at the bottom of the stairs. A detective spoke to Watts and learned about his plan to leave his wife. He said the conversation with Shanann was civil at first but that later "they were both upset and crying" and she planned to go to a friend's house, the court papers said.
When she and the girls did not return home on August 14, investigators ramped up their efforts with help from the FBI and Colorado Bureau of Investigation. Christopher Watts was interviewed by several local television stations, saying he missed his family and wanted them back.
It wasn't until last Wednesday night that he told investigators "he would tell the truth".
In court papers released on Monday, investigators said they learned that Watts was "actively involved in an affair with a co-worker", something he denied in earlier conversations with police.
According to Watts' account, the day of August 13 began with an intense conversation. He said he told his wife that he wanted a separation, then walked downstairs. When he returned, he said he spotted a baby monitor on his wife's nightstand and saw her "actively strangling" Celeste. He said it also showed their other daughter, Bella, "sprawled out on her bed and blue".
Police found surveillance video from a neighbour showing Watts' truck backing into the driveway at 5.27am and then driving away from the house in Frederick, a small town on the grassy plains north of Denver where fast-growing subdivisions intermingle with drilling rigs and oil wells.
Watts, who worked as an operator for Anadarko Petroleum, said he loaded his wife and daughters' bodies into the back seat of his truck and drove to an oil work site about 65 kilometres east of the family's home. He buried Shanann's body and "dumped the girls inside" oil tanks, according to court documents.
Separate documents filed by Watts' defence lawyer last week said the girls' bodies were submerged in crude oil for four days before police found them late on Thursday. Their mother's body was found in a shallow grave nearby, prosecutors said.
The court filing says Watts gave police an aerial photograph and identified three areas where he placed the bodies. Investigators searched with a drone and spotted a sheet that matched other linens in the family home and fresh dirt.
District Attorney Michael Rourke said on Monday that it was too early to discuss whether he would seek the death penalty. Watts will next appear in court on November 16.