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On Friday, prosecutors played in court an FBI video of the confession of Dylann Roof, the self-described white supremacist who is on trial for murdering nine people at Charleston's Emanuel African Methodist Episcopal Church in June of last year.

"I went to that church in Charleston and I did it," Roof says in the tape, laughing as he confesses. "Did you shoot them?" an officer asks. "Yes," Roof answers, laughing again. He said his motive was "to agitate race relations" and that though he "had to do it" he does not feel "glad" about his actions.

The clip sees Roof estimate he killed five people, and he says he did not speak to the victims before opening fire, though he sat through about 15 minutes of a prayer meeting internally debating whether to go through with his plan. "I was sitting there thinking if I should do it or not," he recalls. "I could have walked out. I don't want to say it was spur of the moment."