DENVER (AP) " A Colorado man is due back in court Tuesday to formally learn that he has been charged with the murders of his pregnant wife and two daughters.

Christopher Watts also faces charges of unlawful termination of a pregnancy and three counts of tampering with a deceased human body. It is not clear whether he will enter a plea during the court appearance.

A court filing unsealed Monday say Watts admitted to police that he killed his wife. But he said he strangled her in "a rage" when he discovered she had strangled their two daughters after he sought a separation.

The document says the 33-year-old man then drove his wife and daughters' bodies to an oil work site where he buried 34-year-old Shanann Watts and put the bodies of 4-year-old Bella and 3-year-old Celeste inside an oil tank.

Watts is being held without bail.