Prison parole boards are turning from intuition to computer assessments as states look to cut costs at correctional facilities, reports The Wall Street Journal. At least 15 states have begun requiring some type of risk assessment tool to help parole boards judge whether or not an inmate should be released. Many take the form of software, which may consider 50 or 100 different factors about a person before returning whether it thinks they'd be likely to return to prison during a parole period.

More inmates have remained on parole than in years prior

And the systems appear to be working. According to the Journal, the number of inmates in state and federal prisons fell nearly 1 percent in 2011, a huge leap from lowering just .01 percent the year prior. And early data for 2012 suggests that the number may be growing even higher too. But the reason isn't simply that prisons are releasing more inmates — it's that more inmates are staying out of prison. Around 12 percent of inmates who received parole were re-incarcerated in 2011, a drop from 15 percent of parolees in 2006, reports the Journal.

These automated systems make their decisions off of details such as an inmate's age during their first arrest, whether they believe their conviction to be fair, and their level of education. But the systems aren't perfect. One tool, called Compas, should have its decisions overruled between 8 and 15 percent of the time, its developer tells the Journal.

Though the Journal says that these programs have become more common in the past several years, some states, like Texas, have been using them for far longer. The tools aim to better select who should be released on parole, while helping prisons cut down on their ballooning cost of operations.

Some are concerned about biases in the software

The software is able to do that by besting the decisions of traditional parole boards: parole boards reportedly tend toward considering factors like whether a prisoner shows remorse and the severity of their crime, but those details don't always align with how well they'll do on parole. Murderers and sex offenders are often much less likely to commit another offense than someone guilty of a lesser crime — something that a gut assessment at a parole hearing likely wouldn't speak to.

But while the computerized assessments are meant to improve accuracy, the Journal reports that some experts are concerned that they'll have an implicit racial bias. They say that age of first incarceration and the number of total incarcerations can speak indirectly to a prisoner's race, even if the machine isn't directly considering it. It's part of the reason that parole boards will have to continue overseeing and overruling risk assessments, even if the tools may be increasing accuracy overall.