LOS ANGELES (KABC) -- Conrad Mainwaring's athleticism helped him become an Olympic athlete. It also gave him access to scores of young boys, who hoped to follow in his footsteps.
But today, Mainwaring stands accused of being a serial sex abuser. Those young boys are now grown men coming forward with their stories.
"I couldn't outrun him, I couldn't get around him, he was bigger than me, and I couldn't scream for help," said John Shapiro of Hermosa Beach.
Shapiro wasn't even 10 years old when he first met Mainwaring. It was at a Massachusetts sports summer camp called Camp Greylock.
Mainwaring, who ran in the 1976 Olympics for Antigua, worked as a coach at the camp.
Shapiro went every summer until he was 14.
"That was the first time when the actual molestations had started," Shapiro said.
A few years later Mainwaring was hired at Syracuse University.
Shapiro was an elite high school athlete and trained with Mainwaring there as well. He said the abuse continued.
"He would play all these mental games on me, break me down mentally, like serious mental games where he would just torture me mentally until I gave in," Shapiro said.
Those alleged assaults happened more than 30 years ago, but Shapiro says they created a string of problems in his life that still haunt him today.
"It's years of anguish and turmoil," Shapiro said. "I would have recurring nightmares. My wife would wake me up. I'd be screaming at the top of my lungs. I battle with addictions. I battle with depression."
Shapiro is not alone in his accusations against Mainwaring.
An investigative report by ESPN found more than 40 men who say the former Olympian molested them when they were boys or college athletes, including cases at Caltech and UCLA.
ESPN tracked him down, still coaching young athletes in South Los Angeles.
Last month, Mainwaring was arraigned for sexual battery in L.A.
Meantime, Shapiro has just filed a lawsuit against Camp Greylock and Syracuse University.
A spokesperson for Syracuse University says the school first learned of the allegations against Mainwaring last year.
"We immediately contacted federal and local law enforcement and initiated an independent review of Mainwaring's time on campus," a statement from Syracuse stated. "Based on that exhaustive review, we have been unable to locate or identify any individual who reported the alleged conduct to University officials when it occurred."
And an attorney for Camp Greylock says the current owners of the camp never had any affiliation with Mainwaring.
Shapiro is just hoping to encourage others to come forward.
"There's a lot of other cases out there," Shapiro said. "And the more people who see this, the more will come forward."
SoCal man details alleged sexual abuse by former Olympian accused of molesting dozens