San Diego officer kills woman holding knife to mother's neck

A San Diego police officer shot and killed a 47-year-old woman who was holding a knife to the neck of her 85-year-old mother, police said today.

The incident began Wednesday night when police responded to a domestic-disturbance call and heard screaming from inside a home in the Mira Mesa neighborhood. After forcing their way into the home, officers found the younger woman holding her mother on the floor of a bedroom with a knife at her neck, said Capt. Jim Collins.

When the younger woman refused to drop the knife, an officer fired at her. She was pronounced dead at the scene; her mother was taken to a hospital with non-life-threatening injuries.

The officer is described only as a 15-year veteran. No names have been released.

UPDATE: Police have identified the dead woman as Gianine Desiderio and her mother as Helen Desiderio.

--Tony Perry in San Diego