Dylann Storm Roof Reuters

Dylann Roof, the 21-year-old man accused of killing nine people at a historic black church in Charleston, South Carolina, Wednesday night, told police he nearly abandoned the planned massacre because of how well he was treated by parishioners, according to a report. Roof has been in federal custody since Thursday morning, when authorities captured him on a stretch of highway in Shelby, North Carolina, after a massive manhunt.

Roof, who purportedly sat in on a Bible study at Charleston’s Emanuel African Methodist Episcopal Church for about an hour before he opened fire, said he “almost didn’t go through with it because everyone was so nice to him,” a source familiar with the situation told NBC News. But ultimately, Roof resolved to “go through with his mission,” the source added.

Federal officials conducted preliminary interviews with Roof in Shelby, though he spent Thursday night at Sheriff Al Cannon Detention Center in North Charleston, ABC News reported. Roof confessed that he killed the nine people at Emanuel AME Church, multiple reports said Friday. He was expected to appear at a bond hearing at 2 p.m. ET on Friday.

Sylvia Johnson, who spoke to a relative that survived the shooting, said the survivor told her that Roof reloaded a gun five times during the massacre. “He just said, ‘I have to do it.’ He said, ‘You rape our women and you’re taking over our country. And you have to go,’ ” Johnson told WIS-TV.

Authorities declined Thursday to say what weapon was used in the Charleston church shooting, or if the police officers who arrested Roof in Shelby recovered a firearm from his vehicle. Roof’s uncle, Carson Cowles, said Roof’s father gave him a .45-caliber pistol for his 21st birthday, Reuters reported. It remains unclear if that weapon was used in the attack.

Joseph Meek, a 20-year-old man described as Roof’s childhood friend, said Roof discussed racist ideas and his desire “to hurt a whole bunch of people,” the New York Times reported.

“He was saying all this stuff about how the races should be segregated, that whites should be with whites,” Meek said. “I could tell there was something inside him, there was something he wouldn’t let go. I was trying to tell him, ‘What’s wrong?’ All he would say was that he was planning to do something crazy.”