Evidence-Based Policing Matrix
Individuals – Sherman et. al (1991)
Study Reference:
Location in the Matrix; Methodological Rigor; Outcome:
Individuals; Focused; Reactive; Very rigorous; Mixed effects
What police practice or strategy was examined?
This study, conducted from April 7, 1987 to August 8, 1988, tested the effects of arresting and detaining misdemeanor violence suspects for varying lengths of time. The study was conducted with predominately unemployed suspects concentrated in highly impoverished black neighborhoods in Milwaukee.
How was the intervention evaluated?
The sample consisted of 1,200 eligible cases of probable cause to arrest for misdemeanor domestic battery encountered by a special team of 35 Milwaukee patrol officers. (Cases were considered ineligible if the offender could not be located, the offender had outstanding arrest warrants or restraining orders, or the case involved serious injury or a threat of violence.) The 1,200 suspects were randomly assigned to short detention (2.8 hours), full length detention (11.1 hours), or no detention (no arrest, warning only). The team conducted initial follow-up interviews with victims, usually completed after 7 to 30 days, and additional six-month follow-up victim interviews. They also examined subsequent arrests of the suspects (for violence against any victim) and domestic violence hotline records. The study examined outcomes as of the initial interview and as of the follow-up interview. The researchers also conducted before and after comparisons using a 33-month total surveillance period.
What were the key findings?
Short and long arrest had an initial deterrent effect relative to warnings; 2.2% of the victims of suspects assigned to short arrest and 1.7% assigned to long arrest reported repeat violence upon reunion in comparison to 7% of the victims of suspects who were only given a warning. However, this deterrent effect was short-lived; follow-up interviews and official records showed no differences in recidivism (against the same or any other victim) between the groups at six months. At a one-year follow-up, official records showed higher recidivism among the short arrest group, suggesting that this treatment had a long-term backfire effect. There were no differences in the long-term follow-up between the full length arrest and no detention groups.
What were the implications for law enforcement?
The authors suggest that short-custody arrests for domestic violence in poverty ghetto areas may pose a dilemma between short- and long-term crime control, as it reduces subsequent offending in the short-term but increases it in the long-term. Longer custody arrests have no clear effect in either direction.
Where can I find more information about this intervention, similar types of intervention, or related studies?