Colo. kids were smothered to death, says coroner, mother charged with murder

(CBS/KCNC/AP) DENVER - Two children found dead last spring in their Castle Rock, Colo. home died from asphyxia due to smothering, according to a new report from the coroner in Douglas County.

Kelli Murphy, 41, faces charges in the May 23 deaths of her 9-year-old son, Liam, and her 5-year-old daughter, Madigan. The children were found dead in their beds.

According to CBS affiliate KCNC, the autopsies on the bodies were performed by Dr. Michael Burson, a forensic pathologist. Officials described his conclusion as follows:

"After receiving the results of toxicology tests which were negative, it has been determined that the cause of death for both children is asphyxia due to smothering; the manner of death is homicide."

Authorities said Murphy was the one who called 911 in the case and they said she told the dispatcher she was going to commit suicide. She also allegedly said that her children were in heaven.

Murphy was hospitalized briefly before a court appearance in which she was seen with bandages on her wrists.

She had been going through divorce and bankruptcy proceedings.