Micro Places – Telep et al. (2014)

Study Reference:

Telep, C.W., Mitchell, R.J., &Weisburd, D. (2014). How Much Time Should the Police Spend at Crime Hot Spots? Answers from a Police Agency Directed Randomized Field Trial in Sacramento, California. Justice Quarterly, 31, 905-933.

See also

Mitchell, R. J. (2019). The usefulness of a crime harm index: analyzing the Sacramento Hot Spot Experiment using the California Crime Harm Index (CA-CHI). Journal of Experimental Criminology15, 103-113.

Location in the Matrix; Methodological Rigor; Outcome:

Micro places; General; Proactive; Very Rigorous; Effective

What police practice or strategy was examined?

This study tests the impact that officers can have on crime at hot spots when they spend about 15 minutes patrolling hot spots in a random order (Koper Curve principle). Each day, officers were assigned 1-6 hot spots in their patrol area and were given a random order in which to visit their hot spots. Officers were instructed to visit each of their hot spots for 12-16 minutes when not answering calls for service, and to try to visit each hot spot at least once every 2 hours. While officers were not given specific instructions on what to do while visiting hot spots, they did have daily access to suggested proactive activities through their in-car computers.

How was the intervention evaluated?

This study was carried by a police sergeant, crime analysis unit, and patrol officers of metropolitan police force. The sergeant identified 42 hot spots by examining crime-related calls for service. Hot spots were a street block in length (both sides of the street intersection to intersection). She then randomly assigned 21 of the 42 hot spots to receive the treatment for a 90-day period. She then examined three crime measures for all hot spots: calls for service, Part I crime incidents, and soft crimes incidents to see if treated hot spots show significant improvement compared to control spots.

What were the key findings?

Part I Crime incidents decreased 25% in the treatment hot spots compared to the control hot spots (where they rose 27%). Calls for service declined about 8% in the treatment group and increased about 11%in the control hot spots. Soft crime incidents increased in both the treatment and control hot spots, but the increase was greater in the treatment group. The increase in soft crimes may reflect the increase in officer time spent in the treatment hot spots, which provided officers with increased opportunities to write incident reports for disorder crimes. It could also be the case, however, that the hot spots treatment was not successful in reducing soft crimes.

What were the implications for law enforcement?

The authors suggest a significant overall impact of the hot spots treatment on total calls for service and Part I crime incidents, particularly when comparing the 90-day experiment to the same time period in 2010. This crime reduction effect could also be achieved by officers spending relatively little time in each hot spots. Finally, this study is an example of an in-house experimental evaluation that was conducted without grant funding.

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