Micro Places – Williams & Coupe (2017)

Study Reference:

Williams, S., & Coupe, T. (2017). Frequency vs. length of hot spots patrols: A randomised controlled trial. Cambridge Journal of Evidence-Based Policing1(1), 5-21.

see also for additional analyses:

Williams, S. A. (2015). Do visits or time spent in hot spots patrol matter most? A randomised control trial in the west midlands police. [Unpublished masters thesis]. University of Cambridge.

Location in the Matrix; Methodological Rigor; Outcome:

Micro places; General; Proactive; Very rigorous; Effective

What police practice or strategy was examined?

This study examined the effectiveness of 5-min versus 15-min patrol visits at hot spots of crime and antisocial behavior (ASB) in Birmingham, UK. At the targeted hot spots, officers increased single- or double-crewed foot or bicycle patrol, visited businesses or public places where repeated calls for service were generated, and engaged in community activities. Officers were assigned to deliver 45 minutes of patrol to the target locations per day in doses of either nine 5-minute patrols (“short days”) or three 15-minute patrols (“long days”). Actual delivered dosages averaged five 5-minute patrols on “short” days and two-and-a-half 10-minute visits on “long” days. (Hence, the locations received 24-26 minutes each day on average.)

How was the intervention evaluated?

Seven hot spots were assigned to receive the patrol intervention for 100 days. Each hot spot identified was a grid of approximately 150 square meters. On each of the 100 experimental days, the late shift team was randomly assigned to carry out either the 5-minute or 15-minute patrols at the hot spots. Of these 100 days, short visits were assigned to 43 days, while long visits were assigned to 57 days. (See above regarding planned versus delivered dosages.) The authors evaluated the intervention by comparing the average number of crimes and anti-social behavior calls for service between short and long patrol days.

What were the key findings?

The findings revealed that long patrol visits were associated with an approximately 20% reduction in crime and ASB calls for service compared with the short patrol visits at hot spots. Specifically, the average crime and ASB calls for service were 0.56 per day for 15-minute patrol days, and 0.70 per day for 5-min patrol days.

What were the implications for law enforcement?

This study suggests that frequent 5-min patrols are less effective than less frequent but longer patrols in reducing crime and ASB at hot spots. This supports Koper’s (1995) findings that 10 to 15-minute police visits to hot spots yield greater deterrent effects than shorter visits, even if done less frequently.

Where can I find more information about this intervention, similar types of intervention, or related studies?