Ben Carson has made his transformation from a violent boy to soft-spoken, responsible adult a cornerstone of his campaign, but a CNN investigation found no evidence to back up Carson’s claims of being a problem child.

On the campaign trail, the former neurosurgeon has recounted being an angry juvenile in his native Detroit — stabbing, throwing rocks at people, hurling bricks and beating others with baseball bats.

But through interviews with nine former classmates and friends, CNN was unable to verify any incidents supporting those claims.

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One former classmate told the network: “I don’t know nothing about that… it would have been all over the whole school.” Another classmate told CNN, “I personally do not have knowledge of those incidents… I wondered, ‘When did that happen?'”

A former friend of Carson said if he was as big a hothead as he described, it wouldn’t be a secret.”He got through his day trying not to be noticed… I remember him having a pocket saver. He had thick glasses. He was skinny and unremarkable.”

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“CNN was unable to independently confirm any of the incidents, which Carson said occurred when he was a juvenile,” CNN reporters Scott Glover and Maeve Reston wrote in their online account.

Carson’s campaign declined to provide the network with any corroborating evidence of his violent past, calling the CNN investigation a “witch hunt.”

“Why would anyone cooperate with your obvious witch hunt?” campaign adviser Armstrong Williams wrote in an email last Friday. “No comment and moving on…… Happy Halloween!!!!!”

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Carson is leading the RealClearPolitics average of national polls for the first time, narrowly edging Donald Trump 24.8 to to 24.6.