Chart: Assessing the Risk Scale: Rearrest by Risk Level of Study Participants

The authors developed a risk scale based on attributes associated with criminal recidivism. Once the scale was constructed, they selected the bottom 30 percent as low risk, the top 30 percent as high risk, and the middle 40 percent as medium risk and applied the instrument to the study participants.

To determine whether the risk instrument could discriminate among those classified as low, medium and high risk, they looked at the distribution of arrests across study participants. Of the individuals classified as low risk by the scale, only 22 percent experienced an arrest within 30 months of release. In contrast, of the medium-risk individuals, 49 percent experienced an arrest and, of the high-risk individuals, 72 percent experienced an arrest. The degree of discrimination across risk categories for any arrests was statistically significant. Of the total sample, 48 percent had been rearrested within 30 months of release.