Micro Places – Santos & Santos (2021)

Study Reference:

Santos, R. B., & Santos, R. G. (2021). Proactive police response in property crime micro-time hot spots: Results from a partially-blocked blind random controlled trial. Journal of Quantitative Criminology, 37(1), 247–265.

Location in the Matrix; Methodological Rigor; Outcome:

Micro places; General; Proactive; Very Rigorous; Effective

What police practice or strategy was examined?

This study evaluated the effects of an established proactive policing response in Port St. Lucie, Florida, over a 24-month period from June 2013 to July 2015. The department’s proactive policing strategy identified “micro-time” hot spots, defined as several related incidents within a geographically proximate area that occur within 1-2 weeks. All officers assigned to the district or zone in which a micro-time hotspot was identified were instructed to patrol the area for 10-20 minutes as many times as possible during uncommitted time. Patrol units were instructed to do this throughout a 24-hour period with emphasis on hours of high crime. Officers were also instructed to stop and talk to any suspicious persons walking or in vehicles, make traffic stops, write field intelligence cards, talk with residents about micro-time hot spot prevention, and leave crime opportunity cards when they observe vulnerable targets. Officers were required to enter response activities and outcomes into the department’s intranet system. Response activities included patrol (no suspicious activity), field intelligence stops, suspicious person/vehicle stops, traffic stops, crime opportunity cards, citizen contacts, and arrests. Officer responses to the micro-time hot spots were required for 14 days after the micro-time hot spot was identified.

How was the intervention evaluated?

A partially blocked, randomized experiment was conducted to evaluate the intervention. Officers were not made aware of the experiment as all components of the intervention were previously implemented within the agency. Micro-time hot spots were identified if there were at least two residential burglaries and/or residential thefts from vehicle incidents occurring within 14 days in a .2-mile radius or three of these crimes in 14 days within a .4-mile radius. Micro-time hot spots were then randomized to treatment or control conditions, resulting in 114 treatment hot spots and 103 control hot spots. This study used a no-treatment control group, meaning that police were unaware of the micro-time hot spot and did not respond to it. Four time periods (i.e., within 15, 30, 60, and 90 days of bulletin publication) were used to measure the effect of treatment on additional crimes in the micro-time hot spots. The evaluation focused on burglary and residential theft from vehicle incidents.

What were the key findings?

On average, hot spots received five 20-minute responses per day for 19 days. Compared to the control group, there were 79% fewer crimes in the treatment group in the first 15 days after a micro-time hot spot was identified and 67% less crime in the second 15 days, both of which were statistically significant. Cumulatively, 90 days after the treatment response, there was a 49% reduction in crime in micro-time hot spots. The authors note that no spatial displacement was found.

What were the implications for law enforcement?

The authors suggest that proactive policing strategies, such as hotspot policing, can be effective in reducing crime. To sustain such effects in the long-term, the authors suggest deploying directed patrols in micro-time hot spots that occur within long-term hot spots in combination with non-police responses, such as problem-solving and community-based techniques. By using a no-treatment control group, the authors argue that hotspot policing strategies are more effective than previously estimated. The authors note that the successful institutionalization of the response requirements and accountability processes within the department likely resulted in higher treatment fidelity.

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