His reputation preceded him to the Duluth prison camp, where the prisoners, already inclined to hate anyone involved with law enforcement, gave him the cold shoulder. Preate minded his own business, spending most of his waking hours at his assigned job, scouring pots and pans in the prison kitchen.

A breakthrough occurred a few weeks after Preate's arrival. One of his four bunkmates was writing to a judge, arguing that he should be considered for release after serving eight years. The lawyer in Preate couldn't resist. "Let me take a look at that," he said. Preate ended up filing a formal petition, which got his bunkmate out in 30 days. "They had miscalculated the amount of time the guy was supposed to serve," Preate says. "He couldn't believe it. Well, the word started to spread that I had a little bit of knowledge and . . . was a decent guy."

Prisoners began to detail their cases to him, describing their trials. Preate figured some had gotten what they deserved. But others had had inept lawyers and had been convicted on flimsy evidence. Using the prison's small law library, he helped a few more prisoners be considered for parole or a reduced sentence.

"Frankly, I was shocked by the number who had not received effective counsel," he says. "Even the simplest things, some of those lawyers didn't do: They didn't ask for discovery, they didn't call witnesses, they didn't make the appropriate motions. Our whole system is based on advocacy, and it was clear many of these prisoners had not had competent advocates."

As Preate listened to inmates' stories, the hard-line prosecutor and the hardened criminals started seeing each other in a different light. Preate came to recognize how much he had in common with his fellow inmates: Some had also seen their futures shattered, and, like Preate, missed family and loved ones. "What I was finding was there are a lot of good people in prison who made mistakes," Preate says. "Contrary to public perception that they are a menacing evil," he adds, "the vast majority are not."

As the months wore on, Preate realized that the strident law-and-order approach he had advocated was horribly flawed. Mandatory sentences put drug users behind bars with little or no treatment for their addictions. Lack of substantial rehabilitation programs meant that prisoners weren't challenged to change their behavior.