'Absolutely No Evidence' Shanann Watts Killed Her Daughters: Police Source

Under police questioning not long afterhis pregnant wife and young daughtersvanished from their Colorado home earlier this month,Chris Wattsallegedly admitted he strangled his spouse, Shanann Watts — but he gave a startling reason for doing so.

In response, Chris allegedly claimed, he “went into a rage” and strangled Shanann.

But authorities aren’t buying his shocking explanation. On Aug. 15, two days after Shanann and the girls were reported missing and hours before the announcement that theirbodies had been foundon the property of Chris’ former employer, he was arrested.

The 33-year-old faces charges of first-degree murder in all three deaths, among other charges.

A source close to the investigation tells PEOPLE that Chris’ alleged defense is not plausible.

“There is absolutely no evidence that she killed her children,” the source tells PEOPLE in this week’s issue. “None at all. And there is physical evidence to tie him to their murders. Strangulation is a very personal way to kill someone, with a lot of physical contact. Just based on the preliminary evidence, everything is consistent with him killing them all.”

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Shan’ann Watts (right) and her daughters.Shanann Watts /Facebook

Investigators allegeChris was having an affair with a co-workerbefore murdering his family.

Causes of death in the three killings have not been confirmed and police have not discussed a motive — though, in charging Chris with murder, they dismissed his account of what happened.

“We’ve just begun our investigation in many ways,” the investigation source tells PEOPLE, “but we have a lot of evidence that points straight to Chris.”

He has not entered a plea and his attorney did not respond to PEOPLE’s requests for comment.

source: people.com