San Diego County authorities say a man suspected of killing his mother has been arrested in Arizona.

Sheriff's Lt. Dennis Brugos says 25-year-old David Lucero was arrested in Pima County on Tuesday night for creating a disturbance and for stealing his mother's car. San Diego County investigators are questioning him.

Brugos says Lucero is suspected of killing 53-year-old Margo Lucero at her Valley Center home Tuesday afternoon. Her husband, who's a doctor, found her body. She had extensive injuries but Burgos won't provide details.

Investigators have no motive for the killing. Burgos says deputies went to the home Monday after reports that the son was unstable and acting strangely.

But Burgos says deputies couldn't arrest him because he posed no immediate threat.