Dr. Ben Carson says he was prone to outbursts of violence during his youth until he had a religious experience in the bathroom of his Detroit home.

His former classmates don’t remember that bad-tempered young man, though.

CNN spoke to nine people who attended school with Carson or grew up with him for a sweeping look at the Republican presidential candidate’s formative years. Those people recalled Carson as “quiet, bookish and nerdy.” None said they saw evidence of the angry temperament Carson described in his books and public speeches. All said they were surprised by the incidents of violence Carson has recounted over the years, which included an attempted attack on his mother with a hammer during an argument about clothes, and an attempted stabbing of a friend named Bob in a dispute over what kind of music to play on the radio.

Gerald Ware, a former classmate of Carson’s at Southwestern High School, seemed skeptical about the attempted stabbing in particular.

“Take my word for it: Everyone at Southwestern would know about it if something like that happened,” Ware told CNN.

Another former classmate, Jerry Dixon, told CNN that years ago he heard chatter about an incident similar to the attempted stabbing Carson described but wasn’t sure “if it was just a rumor or what.”

Carson’s campaign declined to provide CNN with further details about the incidents Carson described and dismissed the premise of the new outlet’s story.

“Why would anyone cooperate with your obvious witch hunt?” Carson’s business manager, Armstrong Williams, wrote CNN in an email Friday. “No comment and moving on…… Happy Halloween!!!!!”

Another of Carson’s gritty personal stories was found last month to lack some evidence. The retired neurosurgeon recounted in a radio interview that he was once held up at gunpoint in a Popeye’s restaurant in Baltimore. Baltimore police said they couldn’t locate a police report on the incident due to lack of information, while Carson’s campaign said “details are hazy because that incident did occur over 30 years ago.”

Read CNN’s full report here.