The fatal shooting of man by his brother, an off-duty San Diego police officer, has been determined to be justified, police said Wednesday.

A Chula Vista police lieutenant said the only victim in the case is Officer Bryan Castillo and the only suspect, Wesley Castillo, 34, is dead.

Wesley Castillo is accused of instigating the violent fight last Friday, which started as an argument with his parents.

Castillo suffers from mental health issues, police say, so when he started to get physical with his mother, his brother and SDPD officer Bryan Castillo intervened.

Arming himself with knives, Castillo stabbed Bryan four times. Investigators say Bryan, in self-defense, shot his brother.

Bryan, a 6-year veteran of the SDPD, was found bleeding in the complex's parking lot and was taken to the hospital. He was released this week.