Evidence-Based Policing Matrix
Micro Places – Ariel et al. (2016)
Ariel, B., Weinborn, C., & Sherman, L. W. (2016). “Soft” policing at hot spots—do police community support officers work? A randomized controlled trial. Journal of Experimental Criminology, 12(3), 277-317.
Location in the Matrix; Methodological Rigor; Outcome:
Micro places; General; Proactive; Very rigorous; Effective
What police practice or strategy was examined?
This intervention was designed to test whether the deterrent effects of hot spots policing are dependent on the “hard” threat of arrest and the potential for police officers to apply coercive force to prevent crime, or whether “soft” patrols by civilian personnel, in the form of uniformed Police Community Support Officers (PCSOs), will be similarly effective in reducing crime at hot spots. PCSOs are non-sworn employees of the police and thus cannot carry firearms or other weapons and do not have arrest powers. However, they wear uniforms very similar to police constables and have the power to respond to minor events. In addition, this intervention assessed whether the number of visits to a hot spot was as important for crime reduction as the total number of minutes of police presence across all visits, as measured using GPS data.
How was the intervention evaluated?
In total, 72 hot spots in Peterborough, England, were selected for inclusion in the study, 34 of which were randomly assigned to receive the treatment, while the remaining 38 made up the control group. Each treatment hot spot was assigned to receive three visits by a PCSO each day, lasting 15 minutes each, resulting in a total of 780 visits over the entire 12-month experimental period. These visits were conducted within a limited window designed to capture peak crime days/hours that consisted of Tuesday-Saturday from 3:00pm-10:00pm. PCSOs in treatment hot spots were instructed solely to remain visible at the treatment hot spots to signal police authority. The control hot spots received no proactive patrols but were reactively visited by PCSOs in response to citizen calls for service. To assess the intervention’s effect on crime, the authors utilized calls-for-service and victim-generated crime data in the 24-month period leading up to the experiment and the 12-month window of the experiment itself.
What were the key findings?
Overall, the use of PCSOs at hot spots appears to have a similar effect, in terms of a crime reduction, as patrol by sworn police officers. The treatment group hot spots demonstrated a 64.8% greater reduction in crimes per hot spot than the control areas. The overall effect size of “soft” policing for both calls for service and crime incidents was statistically significant and similar in magnitude to the overall treatment effect of hot spots policing found in systematic reviews of hot spots policing. More simply, the “soft” policing efforts were associated with a 20% reduction in calls for service and a 39% reduction in victim-generated crimes reported to police. While there was evidence of some crime displacement, the intervention prevented far more crime than was displaced. Because the authors were able to monitor dosage using trackers embedded within the PCSOs’ radios, they found that PCSOs visited treatment hot spots an average of 4.65 times per day for approximately 8 minutes each visit, adding up to 37 minutes daily. Comparatively, the control hot spots experienced about 2.66 PCSO visits per day for a total of 15.92 minutes. Given that each additional minute spent daily by a PCSO in a hot spot was associated with, on average, 5 fewer calls for service and 0.7 fewer victim-reported crimes, while each additional daily visit by a PCSO was associated with 34 fewer calls for service and a marginally significant reduction of 4 fewer victim-generated crimes, the authors concluded that reductions in crime at hot spots are significantly influenced by the number of visits by officers rather than by the total duration in minutes of these visits.
What were the implications for law enforcement?
The findings of this intervention suggest that “soft” policing efforts, which do not rely on threats of arrest or the potential for use of coercive force, can be similarly effective in reducing crime at hot spots. Consequently, it may not be necessary to deploy sworn officers for traditional patrol functions, thereby altering resource allocation and potentially staffing strategies. Nevertheless, the authors stress that this study merely presents some positive evidence pointing in this direction and that this one example alone should not provide the basis for drastic reorganization of police agencies. The authors’ findings concerning the frequency of hot spots visits being more influential than the amount of time (duration) spent reinforces the earlier findings of Koper (1995) that short, unpredictable patrol at hot spots is most effective in deterring crime.
Where can I find more information about this intervention, similar types of intervention, or related studies?
- All studies in the Matrix on micro places
- CEBCP page on Hot Spots Policing
- Sherman and Weisburd (1995) study on general deterrent effects of police patrol in hot spots
- Koper (1995) study on optimizing patrol visits to hot spots
- Telep at al. (2014) - How Much Time Should Police Spend at Hot Spots? (Randomized Field Trial)
- Braga et al. (2019) systematic review of hot spots policing
- Williams & Coupe (2017) - Frequency Vs. Length of Hot Spots Patrols