It is two days before Thanksgiving and the guards on Death Row in San Quentin State Prison agree that it is unseasonally hot. Perhaps the embarrassment of being involved in the dispensing of death makes the need for small talk urgent, but it seems to come naturally enough.

Just an hour ago, America’s news stations had gone live to see President George W. Bush pardon a turkey — an annual ritual that spares a lucky bird from the season’s feasting — and in the awkwardness of the moment it is difficult not to see uncomfortable comparisons with the man I am about to meet: a jailbird, an appointment with death and the ability of one man to grant clemency.

This inappropriate thought is still with me as Stanley Tookie Williams shuffles into our meeting place, a bars-and-Perspex-lined cell in the visiting area of America’s most notorious prison. The door is slammed behind him and he thrusts his arms back through a gap so his handcuffs can be safely removed. They take no chances here, when the prisoners have nothing to lose.

Williams is due to be executed by lethal injection on December 13. As co-founder of the Crips, America’s most notorious gang, and murderer of four innocent people, you might expect his passing to go unopposed, save for the usual objections of the anti-death penalty lobby. But you would be wrong.

His execution is causing more than the usual amount of debate in the US, more dissent, more soul-searching. Because the violent, narcissistic thug who was placed behind bars amid much rejoicing 24 years ago is not the same man who will have chemicals pumped into his veins in three weeks’ time. The Stanley Williams who faces death has undergone a dramatic change in personality, a rehabilitation that has seen him develop into an influential writer on the receiving end of five Nobel Peace Prize nominations and four for the Nobel Prize for Literature.

Among America’s intelligentsia and in bars up and down the country, opinion is divided. Has he had 25 years more on Earth than he deserves? Or is he now a force for good who is worth more alive than dead? The awkwardness of our meeting gains momentum as Williams stretches out a huge, lumpen hand in greeting. It is difficult to look someone in the eye when you know they have only a few days left. Dead man walking. Yet he radiates only composure.

“I am coping exceptionally well,” he says. Williams is dressed in blue denim trousers and shirt buttoned tight against his thick neck.

His beard is greying and his gaze, through large, round, rimless spectacles, is firm and relaxed. Only one of us feels uncomfortable.

“The experience is not so different from the moribund life I lived on the outside,” he says. “I was shot up, shot at by police and in constant expectation of attack from my enemies. I have always lived a precarious life, so this is not so different. I used to enjoy fearlessness based on the machismo code of the streets, the ignorance, the bravado.

“Now my fearlessness is based on a sense of redemption, transformation, faith in God and optimism. I have a great sense of serenity — a halcyon sense — in my heart. My peace reflects what I have achieved from a once-wretched condition.”

Williams was born on December 29, 1953, in New Orleans to a loving mother who was abandoned by his father in his first year. When he was 6, his mother went to Los Angeles to build a better life, leaving behind what support network they had. But instead of finding affluence, they landed in the ghetto of South Central LA. Growing up, Williams endured a life of poverty, crime and drugs where exploitation by gangs was the norm.

“I grew to hate gangs,” he recalls. “When I was at home, I was a good boy, and when I wasn’t good my mother gave me a deserved beating. But she was the only one allowed to do that. Away from home, I couldn’t live by her laws or I wouldn’t be alive today. I had to live by the law of the street and I stood up for myself. I made it quite clear that if anyone wanted to beat me up, they’d better be prepared to come back and do it every day because I wouldn’t give in to anybody.”

When he was 17, he and a friend, Raymond Washington, decided to unite their associates in defence against the gangs who regularly attacked and robbed them. They called themselves the Cribs, because of their tender age, but this was soon mispronounced into the Crips.