Dylann Roof facing trial in church killings 00:45 (CNN)Dylann Roof confessed almost immediately to the massacre at Emanuel African Methodist Episcopal Church, according to an FBI video shown Friday at his murder trial in Charleston, South Carolina. "I went to that church in Charleston and I did it," he said with a laugh. Asked how many people he killed that day, the young man in the mushroom haircut calmly replied: "If I was going to guess, 5 maybe. I'm really not sure." "I was sitting there thinking if I should do it or not for 15 minutes," Roof said, according to the video.