“A picture emerges of a crisis that began on November 29, when in the course of a performance for a class taught by visiting instructor Ron Athey, a graduate student entered a classroom at UCLA’s Warner building where roughly thirty other students were gathered. The student, wearing a coat and tie, produced either a gun or a convincing replica of one, put what looked like a bullet into the weapon, spun the cylinder, and held it to his head, Russian-roulette style. He pulled the trigger, but the gun did not fire. The student then left the room; while he was out of view, a shot was heard, at which point he returned, now apparently unarmed.”