DENVER (AP) — A Colorado man told police that he killed his pregnant wife in “a rage” when he discovered she had strangled their two daughters after he sought a separation, according to an arrest affidavit released on Monday shortly after prosecutors charged the man with his family’s murders.According to the affidavit, Christopher Watts told his wife, Shanann, that he wanted to separate when she returned from a business trip early on the morning of Aug. 13.Watts told police that he walked downstairs after the conversation.When he returned to the couple’s bedroom, Watts said he checked a baby monitor on Shanann’s nightstand and saw his wife strangling their youngest daughter while their oldest daughter sprawled on her bed, looking blue.Watts, 33, said he then “went into a rage” and strangled his wife. 60 PHOTOS Shanann Watts and her two daughters killed in Colorado See Gallery Shanann Watts and her two daughters killed in Colorado A photograph sits amid the tributes as they grow outside the home where a pregnant woman, Shanann Watts, and her two daughters, Bella and Celeste, lived Thursday, Aug. 16, 2018, in Frederick, Colo. The woman’s husband, Christopher Watts, has been arrested on suspicion of killing his…