CHARLESTON, S.C. —– Dylann Roof wanted the world to know he hated black people and thought they were criminals. He thought about attacking drug dealers, but they might shoot back. So, he told the FBI, he picked a historic black church in Charleston he had learned about online. In a videotaped confession shown Friday during his death penalty trial, Roof laughed several times and made exaggerated gun motions as he recounted the massacre.