OBJECTIVES: Many agencies use risk assessment instruments to guide decisions about pretrial detention, postconviction incarceration, and release from custody. Although some policymakers believe that these tools might reduce overincarceration and recidivism rates, others are concerned that they may exacerbate racial and ethnic disparities in placements. The objective of this systematic review was to test these assertions.

HYPOTHESES: It was hypothesized that the adoption of tools might slightly decrease incarceration rates, and that impact on disparities might vary by tool and context.

METHOD: Published and unpublished studies were identified by searching 13 databases, reviewing reference lists, and contacting experts. In total, 22 studies met inclusion criteria; these studies included 1,444,499 adolescents and adults who were accused or convicted of a crime. Each study was coded by 2 independent raters using a data extraction form and a risk of bias tool. Results were aggregated using both a narrative approach and meta-analyses.

RESULTS: The adoption of tools was associated with (a) small overall decreases in restrictive placements (aggregated odds ratio [OR] = 0.63, p < .001), particularly for individuals who were low risk and (b) small reductions in any recidivism (OR = 0.85, p = .020). However, after removing studies with a high risk of bias, the results were no longer significant.

CONCLUSIONS: Although risk assessment tools might help to reduce restrictive placements, the strength of this evidence is low. Furthermore, because of a lack of research, it is unclear how tools impact racial and ethnic disparities in placements. As such, future research is needed.