Authorities say a 46-year-old man who was fatally shot by San Francisco police had a history of mental illness.
Bui allegedly stabbed a teenage girl at his Portola neighborhood home Wednesday afternoon. Police say officers who responded opened fire when Bui refused repeated orders to drop a knife and came at them with his arm raised.
He was taken to San Francisco General Hospital, where he was pronounced dead. The girl was treated for non-life threatening injuries.
Gascon said he believes the officers, who have not been identified, acted legally.