Former heavyweight champion turned cautionary tale Mike Tyson has been described as a lot of things – a thief, a rapist, an animal unleashed and, during his professional heyday, the most terrifying fighter on the planet – but rarely has he been presented as sympathetic.

That changes in James Toback’s Tyson, a featured selection at the San Francisco International Film Festival, in which the once dominating boxer tells his story in painfully candid detail, acknowledging his eventual ambivalence toward the sport that made him a superstar and repeatedly professing his desire to lead a better, more righteous life.

As he has throughout his fascinating but troubled career, he denies raping Desiree Washington, for which he served three years in prison, but freely admits to robbing drug dealers at gunpoint during his formative years in Brooklyn. And he recalls with surprising tenderness the years he spent training with mentor and father figure Cus D’Amato, who died before he could see his star pupil win his first title fight at the age of 20.

Did Tyson ever enjoy boxing? It’s a legitimate question. Though he recalls his eagerness to please D’Amato and his passing desire to become a champion, Tyson makes it clear that he lost his passion for the sport in 1990, a full 15 years before his 2005 retirement. (Before bowing out unceremoniously after a loss to a journeyman contender, he said he no longer had “the fighting guts or the heart.”) He fought for money to support his family, but rarely if ever for his own gratification.

There are times when Tyson’s behavior seems nothing less than monstrous – at a 2002 pre-fight press conference when he threatens to sexually assault a reporter, and during the infamous ear-biting incident that rendered his second bout with Evander Holyfield a macabre spectacle. Tyson doesn’t shy away from either, offering plausible explanations for his animalistic outbursts, and it’s hard not to feel some measure of compassion for him.

How much depends on your willingness to believe in the softer, gentler side of a man who has spent his life and career doling out pain, both emotional and physical. (During one sequence that elicited a smattering of cheers and nervous giggles from the festival audience, Tyson recalls turning his lethal fists on promoter Don King as a pair of elderly white women looked on in horror.) Tyson’s thoughtful ramblings don’t absolve him of the guilt he claims to feel, but they do create a memorably harrowing portrait of a man tormented by his fears and used by an ever-changing cast of “leeches” and hangers-on.