Arthur Folasa Ah Loo was killed when a man who was believed to be part of a peacekeeping team for the protest shot at a person brandishing a rifle at demonstrators, accidentally striking Ah Loo.

A bystander was fatally shot after security members at the demonstration confronted a man who was running toward the crowd with an AR-15-style rifle, the police said.

Police said Sunday that someone wearing a brightly colored security vest was aiming at a man who had peeled off from the crowd and was holding a rifle.