Judges in Missouri will now receive a risk score, estimating statistically the likelihood that an offender will commit a crime again, similar to a credit score which estimates a change of default on a loan, with ever pre-sentence report. While the score is advisory only, it is expected to have a great impact on sentencing practices, one would hope for the better.
The downside is that the risk of reoffense may overweigh other objectives of the criminal justice system like impartiality and punishment. For example, it will likely tend to result in heavier sentences for poor defendants, than for middle class ones, for the same crime, and is likely to have an indirect effect of skewing sentencing decisions such that blacks serve longer terms than whites, even if race is not expressly considered.
The risk of reoffense may also fail to reflect the severity of the crime that may be committed upon release. It would be better if a hundred people commit another shop lifting or drug possession offense, than if one commits a rape or murder upon release.