David Crary of the Associated Press has this story on the growth of faith-based prisons. A snippet (emphasis added):

Even as they proliferate, fueled by the fervor of devout volunteers, these programs are often criticized. Evidence that they reduce recidivism is inconclusive, and skeptics question whether the prevailing evangelical tone of the units discriminates against inmates who don't share their conservative Christian outlook.

However, evidence is strong that violence and trouble-making drop sharply in these programs, and they often are the only vibrant rehabilitation option at a time when taxpayer-funded alternatives have been cut back.

And later in the story:

Prison Fellowship's president, former Virginia attorney general Mark Earley, said any move to curtail evangelicals' volunteer work in prisons would undermine the prospects for greater nationwide emphasis on rehabilitation.

"If you excluded faith-based groups, you're excluding the largest number of people willing to be involved," he said. "There's not a whole lot of other people lining up at the prison doors."

Link: Prison Fellowship Ministries