Chris Watts, 33, was arrested last week on suspicion of first-degree murder and the threefold manipulation of a human body, police said. He is being held at the Weld County jail without bail, his next court date is scheduled for Tuesday.
Under Colorado law, prosecutors must file charges against Watts Monday or let him go.
Shanann Watts, 34, and daughters, Bella, 4, and Celeste, 3, were missing Monday from their home in Frederick, a town of about 8,600 people 30 miles north of Denver.
Prosecutors have not stated a motive in the killings. A judge sealed the detention affidavit, which could include information about why Chris Watts was arrested and other details.
The results of the autopsy were not published, but documents filed on Friday in Chris Watts arrest show that some of the victims were strangled.
Chris Watts 'lawyers on Friday asked a court to ask pathologists to brush the little girls' necks and hands for DNA, court records show. The judge refused, saying that he would not tell the coroner how to do his job.
In a Monday morning interview on ABC's "Good Morning America," friend Nicole Atkinson said she dropped Shanann off on Monday, August 13, at 2 am Business Trip
"She walked in, turned around and waved to me and closed the door, "said Atkinson.
Shanann did not return calls that day and missed a medical appointment that was expected to be her unborn child's heartbeat, Atkinson said. Shanann was 15 weeks pregnant
Atkinson said she contacted Chris Watts, but he did not seem to be as worried as she had thought. Atkinson said she then contacted the police.
"We had an emotional one Conversation, I'll leave it at that, "Watts told a reporter who asked if they had argued. I just want them to come back.
Watts said he had gone to work at 5:15 that day and was not worried when his wife did not answer his lyrics and phone calls since she had just returned from outside the city.
But he did Worried, he said, when one of her friends contacted him around noon and said she did not respond to news.
"I went into the house and – nothing," said Chris Watts KMGH. "She was not here. The children were not here. "
Shanann Watts's body was found on Anadarko Petroleum's property, the authorities said, and the girls' bodies were in an" oil well filled with petroleum for several days, "the lawyers said by Chris Watts in a lawsuit.
Chris Watts was killed by Anadarko Petroleum on Wednesday, August 15, corporate communications director Jennifer Brice said Watts was arrested the same day by the Frederick Police Department
CNN's Faith Karimi and Joe Sterling contributed to this report.