A "distraught" dad came home to find his 4-month-old daughter and 14-year-old daughter dead in their California home, and their mother alive but unresponsive.
No charges have been filed, but Ontario, California, police Sgt. Bill Russell said at a news conference on Wednesday that police are looking at the mother as the person "responsible."
The mother, who has not been identified, allegedly left suicide notes -- one in the house and one in the car -- saying she intended to kill the children and herself, Russell said. He did not elaborate on what the notes said.
The gruesome discovery was made on Tuesday, prompting the father to call police, Russell said. Ontario is about 40 miles east of Los Angeles.
The mother was taken to a hospital and is in stable condition, but has not been able to provide a statement to police, Russell said.
Russell said the children's father was never detained and gave a voluntary statement to police. The last time he saw his two children alive was when he let for work that morning, Russell said.
"He's lost everything at this point," Russell said of the father, calling the case a "horrible tragedy."
While the girls' cause of death has not been determined, police have called their deaths a double homicide. There was a struggle at the scene which may have played a factor in the deaths, Russell said.
Russell said "the mother was dealing with depression" but he did not elaborate or say if she was being treated.