An acquaintance of the man who killed nine African-Americans in a South Carolina church talked to Greta Van Susteren about the killer's apparent motives. 

Justin Meek's brother, Joe, is a longtime friend of Dylann Roof and both had spent time with the accused killer in recent days. 

Justin Meek said on "On the Record" that Roof came to his home on Tuesday to "chill" and then went to a lake with his brother.

He explained that Roof had previously shown them the gun believed to have been used in Wednesday night's mass shooting.

Meek recalled Roof saying that his mother took the gun away from him, but he had taken it back. 

PHOTOS, LATEST: SC Church Shooting Suspect Taken Into Custody

'Completely Shameful': Jindal Blasts Obama's Gun Violence Comments

"She didn't trust him with it," said Meek, adding that he was shocked to hear that Roof was the suspect in the brutal murders.

Van Susteren asked Meek why he thinks Roof selected Charleston's Emanuel African Methodist Episcopal Church as the target. 

"I think he is racist," he replied. 

Previous reports indicated that Roof had been given a .45 caliber handgun by his father as a 21st birthday present in April. 

Joe Meek told Associated Press that he believes Roof bought the handgun himself, using birthday money from his parents. 

From AP:

Roof's childhood friend, Joey Meek, called the FBI after recognizing him in the surveillance footage, down to the stained sweatshirt he wore while playing Xbox videogames in Meek's home the morning of the attack.

"I didn't THINK it was him. I KNEW it was him," Meek told The Associated Press after being interviewed by investigators.

Meek said Roof recently used his birthday money to buy a Glock pistol. When the two of them were drinking together a few weeks ago, Roof began railing about black people and remarked that he had "a plan," Meek said. He did not say what the plan was, but Meek said it scared him enough that he took the gun out of Roof's car and hid it in his house until the next day.

Roof was arrested without incident Thursday in Shelby, North Carolina, after a motorist spotted him and tipped police, and waived extradition back to South Carolina, where he was held pending a bond hearing, Charleston Police said.

His previous record includes misdemeanor drug and trespassing charges. He wasn't known to the Southern Poverty Law Center in Montgomery, Alabama, and it's not clear whether Roof had any connection to the 16 white supremacist organizations operating in South Carolina, but he appears to be a "disaffected white supremacist," based on his Facebook page, said the center's president, Richard Cohen.

Meek said he and Roof had been best friends in middle school, where "he was just a quiet kid who flew under the radar." Roof then disappeared and showed up again several weeks ago, seeming even more quiet and withdrawn.

But on his Facebook page, Roof displayed the flags of defeated white-ruled regimes, posing with a Confederate flags plate on his car and wearing a jacket with stitched-on flag patches from apartheid-era South Africa and Rhodesia, which is now black-led Zimbabwe.

And when Meek asked what was troubling Roof, "he started talking about race," the friend said.

Watch the interview with Justin Meek above.