Police lead confessed Charleston, South Carolina, church shooter Dylann Roof into the courthouse in Shelby, North Carolina, on June 18, 2015. Roof, 21, is accused of killing nine people at a historic African-American church, an attack U.S. officials are investigating as a hate crime. Reuters/Jason Miczek

Friends of the 21-year-old white man who attacked a historically black church in Charleston, South Carolina, this week say they feel guilty about not doing more to prevent racially motivated violence that left nine people dead. Dylann Roof, the shooter who was captured by police Thursday, had spoken to his friends about wanting to start a race war in the weeks before he shot up Emanuel African Methodist Episcopal Church, according to several media reports.

One of Roof’s childhood friends, 20-year-old Joseph Meek, told multiple news outlets that Roof had changed over the years and shared racist ideas and plans to “hurt a whole bunch of [black] people.” Meek said he had reconnected with Roof this year.

“He was saying all this stuff about how the races should be segregated, that whites should be with whites,” Meek said in interviews. “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.”

Roof was arrested Thursday in North Carolina after federal and local law enforcement identified him as suspect in the shooting that killed nine church members, including the pastor, the Rev. Clementa Pinckney. Officials said Roof confessed to carrying out the massacre in an interrogation, CNN reported.

Meek said he and his girlfriend, Lindsey Fry, did not take Roof seriously at first. But they were still worried enough to take his away a .45-caliber handgun that Roof purchased with birthday money several weeks ago. Because Meek was on probation and is prohibited from possessing a firearm, Fry persuaded her boyfriend to return Roof's weapon.

“I feel we could have done something and prevented this whole thing,” Fry told the New York Times.

Another friend of Roof’s, Dalton Tyler, told the Times that he’d begun talking about starting “a civil war.” But like Meek and Fry, Tyler did not take Roof seriously. “I was just like, ‘You’re stupid,’ ” Tyler said. “He was a racist; but I don’t judge people.”