Killer dad Chris Watts "confessed to fatally strangling his wife in a rage but still maintains she killed their daughters

Following days of denial, father-of-two Chris Watts confessed to killing his pregnant wife in a rage. He reportedly made the startling admission after having a heart-to-heart conversation with his father.

Chris Watts, 33, had shifted his story multiple times to police after the disappearance of his wife Shan'ann, 34, and their two young daughters on August 13. He originally denied knowing where his family was, telling authorities he and his wife were involved in a "civil" and "emotional" conversation ahead of their disappearance. He even went on TV to make an emotional plea for their return.

However, when confronted with evidence that he was having an affair, People reports that Watts told officers he "would tell the truth after speaking with his dad". After the two spoke, he confessed to killing Shan'ann but still insisted she killed the pair's children.  

He then told police he'd taken the bodies of his wife and daughters to an oil field where he worked.

Watts was arrested and charged with first-degree murder in the deaths of Shan'ann, Celeste, 3, and Bella, 4, - at their home in Frederick, Colorado. He told police that he and his wife argued "emotionally" about separating on the morning of their disappearance and that his wife strangled both of their children to death. Watts claims he then strangled Shan'ann in a fit of rage. He said that after he told his wife he wanted to separate, he watched as she strangled Celeste while Bella was "blue", her lifeless body in a bed nearby.

This confession came after investigators learned he was allegedly having an affair with a co-worker. He denied the affair but an investigation confirmed otherwise. Once Watts was confronted with this information, he made the request to speak to his father who was at the police station at the time. 

He then confessed "the truth" of what happened. But investigators say Watts is lying.

A source close to the investigation told People.

The theory that she [Shan'ann] did it doesn't hold any water.

There is absolutely no evidence that she killed her children.

Meanwhile, Watts' lawyers are asking the court to investigate whether prosecutors have leaked damaging information about their client to the press. Prosecutors have denied the accusation.  

Watts is also charged with tampering with evidence for allegedly burying his wife in a shallow grave 35 miles from home and dumping his two daughters into a tank filled with crude oil. 

Prosecutors in the case are asking the judge not to reveal the autopsy report before his murder trial begins. 

The confessed killer is now apparently severely depressed after being kept in isolation after more than a month in jail. A source at the Weld County Jail in Colorado confirmed that the 33-year-old murder defendant is now on suicide watch.

A source told People:

He's not doing well at all. The gravity of the situation has hit him like a ton of bricks. Depression is setting in, and he's despondent.