As part of those visits, inmates tell the group about their cases and their lives behind bars. For the past several years, Ms. Dallaire has been one of those inmates.

“She was the perfect teaching case,” the judge noted in his chambers recently.

Ms. Dallaire’s arrest for selling and possessing crack cocaine was not her first. Seven years earlier she had been arrested on possession of a similar amount of crack and while in college she had thrown a glass in a barroom brawl, causing an injury. The result was that at her third arrest she was a “career criminal” under the guidelines, tripling her sentence.

Judge Lagueux, nominated to the bench by President Ronald Reagan, made clear at Ms. Dallaire’s original sentencing that he was acting against his own better judgment. “This is one case where the guidelines work an injustice, and I’d like to do something about it but I can’t,” he said then from the bench.

Ms. Dallaire, who graduated from Central Connecticut State University in New Britain, says that she was never very interested in drugs, only in the pocket cash that dealing them provided. Her parents had divorced, the local economy had tanked and she had fallen in with a bad crowd.

“I made a lot of stupid and ridiculous decisions,” she said. She declared herself lucky to have been caught and sent to prison — just not for 15 years. “I deserved to go to prison,” she said. “Thank God I got time. I got my priorities straight.”

Ms. Dallaire turned prison into an opportunity to serve others. She made and donated thousands of blankets, hats and pillows to a children’s oncology ward. She organized the inmates to decorate Christmas trees that were auctioned to companies with the proceeds to a cancer charity. She got 600 inmates to march around the prison yard as part of a drive against breast cancer, raising more than $1,500 from their small earnings.