Evidence-Based Policing Matrix
Individuals – Sherman & Berk (1984)
Study Reference:
Location in the Matrix; Methodological Rigor; Outcome:
Individuals; Focused; Reactive; Rigorous; Effective
What police practice or strategy was examined?
The Minneapolis Police Department tested the effects of different domestic violence responses on recidivism. Three police responses to simple assault were randomly assigned to legally eligible suspects: an arrest, ‘advice’ (including, in some cases, informal mediation), and an order to the suspect to leave for 8 hours.
How was the intervention evaluated?
The intervention was evaluated with a randomized controlled trial. The behavior of the suspect was tracked for 6 months after the police intervention, with both official data and victim reports. Research staff contacted the victims for a detailed face-to-face interview, to be followed by telephone follow-up interviews every two weeks for 24 weeks. The interviews were designed primarily to measure the frequency and seriousness of victimizations casued by the suspect after the police intervention. Only misdemeanor domestic assaults where both the victim and suspect were present when the police arrived were included in the study.
What were the key findings?
The official recidivism measures show that the arrested subjects engaged in significantly less subsequent violence when compared to the baseline treatment of separation with 13 percent committing a repeat assault compared to 26 percent. The mediation treatment was statistically indistinguishable from the other two based on police data. The victim report data showed that the arrested subjects committed significantly less subsequent violence (19%), compared to those who were advised (37%). According to vicitm data, those administered ’advice‘ or mediation were most likely to recidivate.
What were the implications for law enforcement?
Police should not be reluctant to make arrests in domestic assault cases for fear that an arrest could make the violence worse. The results indicate that only three of the 136 arrested offenders were formally punished by fines or subsequent incarceration. This suggests that arrest and initial incarceration alone may produce a deterrent effect, regardless of how the courts treat such cases, and that arrest makes an independent contribution to the deterrence potential of the criminal justice system.
Where can I find more information about this intervention, similar types of intervention, or related studies?