EL CAJON, Calif. — Police in this city near San Diego say they were responding Tuesday to a report of a man acting erratically when he pulled something from his pocket and took “a shooting stance,” prompting officers to fatally shoot him, authorities said.

Relatives identified the man as Alfred Olango and described him as “mentally challenged,” saying that his sister had called police to say that he was walking in traffic and acting erratically.

The police and the county district attorney will both investigate the shooting, officials said, even as residents called Wednesday for authorities to release video footage showing what happened.

Olango’s death came as tension lingers in Charlotte, North Carolina, over a deadly police shooting there a week earlier, which sparked a renewed focus nationwide on how officers use deadly force, and it prompted protests and a prayer vigil in this city in southern California.

When police responded, Olango initially “refused multiple instructions by the first officer on the scene and concealed his hand in his pants pocket,” Jeff Davis, the city’s police chief, said during a news conference describing the shooting.

Davis said a second officer arrived and was prepared to use a Taser to stun Olango, who was pacing while officers spoke to him.