Concord — The man put away the letter after he read it. He had requested a pen pal, an adult pen pal, to write him here at the prison, but instead some kid had written.

But four hours later, in a circle of a dozen other sex offenders, Ken W. VanCoppenolle learned they already knew. Why, the other men demanded, did he not tell them immediately? Why did they find out only because the mailroom came across the letter and sent up an alert?

"I think he wasn't planning on saying anything," one of them said.

"I can't understand why you held onto that."

"By keeping a secret, you're jeopardizing your program."

Therapist Kim Marsh spoke up. "Why do we say that, 'no secrets'?"

VanCoppenolle, who is serving a two- to five-year sentence for aggravated felonious sexual assault in Grafton County, stared at the concrete floor, then began to weep.

So I wouldn't be ashamed, he said softly.

Another sex offender tossed him a roll of toilet paper to wipe his eyes. The men had taken VanCoppenolle to task because they, too, understand the danger of not confronting themselves. They, too, were normal-looking guys wearing green uniforms, sitting in orange plastic chairs, speaking about terrible acts they committed.

"Here, you're getting rebuked by us," said Marc Kempton, who is serving a two- to four-year sentence for aggravated felonious sexual assault in Hillsborough County. "On the streets, you know what can happen."

It did happen. It was how they wound up in this room of the New Hampshire State Prison, staring at a poster with a round chart labeled "the deviant cycle." The chart is no abstraction: Each of the men has lived through that cycle, has gone from the portion labeled "safe" to the one labeled "offending," like hands on a clock.

Now, they say they try to help one another understand what led to their crimes — and how they can keep themselves out of trouble when they leave prison.

"Everybody has a pattern that led to their offense," Kent Dunn, who is serving an eight- to 20-year sentence for raping a woman in Hillsborough County, said in an interview after the meeting. "And finding what got us to here," he said, will help prevent him from re-offending.

Most sex offender treatment programs around the country, including Vermont's, are modeled on the same theory as New Hampshire's: that sexual deviancy is a pattern of behavior that can be controlled.

Offenders learn to recognize high-risk situations — such as being alone with a child — as well as the emotional states that precipitated their crimes. The hope is that their awareness will help them "break the cycle" that can lead to more crimes.

New Hampshire's program includes twice-a-week group therapy sessions like the one in Concord, as well as classes designed to help offenders control sexual arousal and learn to empathize with their victims. Treatment lasts about 18 months for the roughly 85 inmates now in the more intensive program. A six-month program serves about 15 lower-risk inmates.

Inside and outside prison, rehabilitation programs are designed and run by professionals who aim to help raise offenders' awareness of their tendencies and give them the skills they need to keep them under control. But the success of treatment also hinges on the contributions of other offenders.

The men in the intensive program live in the same unit, a segregation that helps build a "therapeutic community," said interim program director Daniel Millis. In other words, he said, "they call each other on their behavior."

New Hampshire has not undertaken a study to track the success rate of the program's participants once they leave prison, but studies of similar programs, including Vermont's, suggest that treatment can play a significant role in reducing recidivism rates.

Sex offenders have incentives to participate in the programs. New Hampshire, for instance, won't consider granting parole until they complete the program, said corrections spokesman Jeffrey Lyons. As part of plea agreements, some sex offenders can reduce their minimum prison sentences if they complete the program.

Enrolling in treatment requires that participants admit what they did and admit that they hurt someone. It can be a significant step for sex offenders, who often find ways to rationalize and justify their behavior, experts say. Offenders who maintain their innocence cannot participate.

"What we do is look at their offense and break it down" to the thoughts and feelings that preceded it, said another of the prison's therapists, Judy Mann. "Thoughts go to feelings and feelings go to behavior."

In the group run by Mann and Marsh that met one recent afternoon, each man introduced himself to a visiting reporter and photographer by way of his name and crimes.