Dylann Storm Roof, the Columbia area resident suspected in the Charleston church killings, was an increasingly troubled youth who appeared isolated and adrift to friends.

Roof, 21, was described Thursday as a once non-threatening youngster who kept largely to himself. But his quiet manner and racial views changed as he grew older and left schools in the Red Bank area of Lexington County and the Shandon area of downtown Columbia.

His arrest in connection with the mass murder of nine African-Americans late Wednesday came after a brush with Midlands police in February.

That surprised some acquaintances but not others. He was arrested Thursday morning in Shelby, N.C., after an overnight regional manhunt.

Dalton Tyler, who described himself as Roof’s roommate, told ABC News that Roof was “planning something like that for six months.”

“He was big into segregation and other stuff,” Tyler said. “He said he wanted to start a civil war. He said he was going to do something like that and then kill himself.”

The gunman was quoted as saying before he fired in the church, “I have to do it. You rape our women and you’re taking over our country. And you have to go.”

Some who knew Roof as a youngster are surprised that he became enamored with racial separation.

“I never looked at him like he was trying to actually harm somebody,” said Caleb Brown, who attended elementary and middle school with Roof.

“He wasn’t a loner or anything. He was just an average kid in school. He would be the class clown for attention. There is nothing I could see that I would say straight-faced that there was something wrong with that kid.”

Roof went through a variety of family issues but never talked about them, Brown said.

“He wasn’t an expressively emotional person,” Brown said. “If there was anything wrong with him, I got the impression that he was the kind of person that suppresses any emotions.”

Roof didn’t join other students who went on to college and careers, and it’s unclear what his current address is.

He lived on and off with his father in Hopkins in lower Richland County, according to law enforcement officers. His grandfather is respected Columbia real estate lawyer Joseph Roof.

The suspect told police in February during his arrest for possession of illegal narcotics that “his parents were pressuring him to get a job,” according to a police incident report.

Roof is facing charges for drugs in Lexington County after being arrested Feb. 28 by Columbia police at Columbiana Centre mall, according to an arrest warrant.

He had a bottle containing what police believe to be unprescribed suboxone pills, the report said. Suboxone is commonly used to treat opiate addiction.

Police went to the mall after security officers there notified them that Roof was going into stores asking “out-of-the-ordinary questions” such as the number of employees and closing time, the incident report said.

During the conversation with authorities, Roof “was becoming more nervous-acting” before allowing a search in which the pills were found, it said. He was banned from the mall at the time.

His lawyer in that case, Kenneth Mathews, declined comment.

On April 26, Roof was charged with trespassing after he was found in the mall’s parking lot, and he received an additional three-year ban.

U.S. Attorney Loretta Lynch said Justice Department officials and the FBI are investigating the Charleston shootings as a hate crime.

The Anti-Defamation League said in a statement that there is little doubt a hate crime occurred. A photo of Roof on his Facebook page shows him wearing a jacket with two patches used by white supremacists in Africa, it said.

But Roof’s Facebook page shows African-American friends.

Brown, who is of mixed race, said Roof never overstepped racial boundaries with him.

“I’ll get into a fight if you call me something,” said Brown, a student at the University of Houston. “But Dylann never did that. He never overstepped his boundaries with me, and I have easy boundaries to step over.”

But Roof’s attitude changed recently, some friends said.

And, according to Reuters News Service, the suspect’s uncle, Carson Cowles, said Roof was given a .45-caliber pistol by his father as a 21st birthday present in April. Efforts by The State to reach Roof’s father and grandfather were unsuccessful.

Cowles said he recognized Roof in a photo released by police and described him as quiet and soft-spoken, according to Reuters.

Roof attended several schools in the Columbia area, including Hand Middle School, where classmate Chris Yogodzinski said he remembers the slightly-built Roof as an odd youth who didn’t appear to have many close friends.

“The whole world is going to be looking at his family who raised this monster,” Cowles, said Thursday, wiping away tears at his Gaston home. While Roof was quiet and “did stay a lot to himself,” Cowles said, his mother “never raised him to be like this.”

Even as he described Roof as a quiet young man who kept out of trouble, Cowles shook with anger at the thought that his nephew could have carried out the crime with which he is accused.

“I’d be the executioner myself if they would allow it,” he said.

Yogodzinski, a college student in Pennsylvania, said he attended sixth grade with Roof at Hand Middle.

“You never think someone you knew so long ago is going to pop up in the news in this kind of way,” Yogodzinski said. “I’m just shocked.”

Roof was a student in eighth grade at Carolina Springs Middle School and then ninth grade at White Knoll High School in Lexington County before leaving, officials at Lexington 1 said.

Other schools he attended include Rosewood Elementary, Hand Middle and Dreher High in Columbia – but he did not graduate from any Richland 1 high school, Richland 1 spokeswoman Karen York said.

Staff writer John Monk and The Washington Post contributed to this story.