By Keith Coffman
DENVER (Reuters) - A Colorado oil worker charged with murdering his pregnant wife and two young daughters told investigators following his arrest that he killed his wife after she strangled the children, court documents showed on Monday.
Chris Watts, who had been involved in an extramarital affair with a co-worker, said during a police interrogation that his wife, Shannan, strangled their daughters Bella and Celeste after he announced that he wanted a separation, according to an arrest affidavit filed in the sensational case.
"While in the bedroom, via a baby monitor located on Shannan's night stand, he observed Bella 'sprawled' out on her bed, blue, and Shannan actively strangling Celeste," Frederick Police Officer Matthew James wrote in the affidavit.
"Chris said he went into a rage and ultimately strangled Shannan to death," James wrote.
Watts, 33, was formally charged on Monday with five counts of first-degree murder, one count of unlawful termination of a pregnancy and three counts of tampering with a deceased human body. The five murder counts include alternate legal theories available to prosecutors under Colorado state law.
Watts has been held without bail since his arrest last week for the murders of his family that has fixed national attention on the tiny former mining town of Frederick, now a bedroom community of 13,000 people.
Shannan Watts and the two girls were reported missing by a family friend on Tuesday from their home in Frederick, about 30 miles (50 km) north of Denver.
Watts said in an interview with TV station Denver 7 on Tuesday that he was torn up inside about his family going missing and pleaded for their return.
"I just want them to come back," Watts told Denver 7. "My kids are my life. Those smiles light up my life. I want everybody to just come home."
Prosecutors say the body of Shannan Watts was discovered buried in a shallow grave and his daughters had been stuffed into oil tanks at the facility where Chris Watts worked until his arrest.
According to the affidavit, Watts told detectives he had disposed of the bodies by loading them into his pickup truck and driving them to the field. The affidavit says Watts told police where the remains could be found.
Neither Watts nor his court-appointed attorney have commented publicly on the case since his arrest. He was due in court on Tuesday for an arraignment on the charges.
(Reporting by Keith Coffman in Denver; Additional reporting by Jon Herskovitz in Austin, Texas; Writing by Dan Whitcomb in Los Angeles; Editing by James Dalgleish and Chris Reese)