General deterrent effects of police patrol in crime “hot spots”: A randomized, controlled trial

TLDR

Many criminologists doubt that the dosage of uniformed police patrol causes any measurable difference in crime. The study tests whether increasing police patrol dosage in crime hot spots reduces crime and disorder. The experiment doubled patrol presence in 55 hot spots over a year, with 7,542 hours of systematic observation, though seasonal variation was noted. The increased patrol dosage led to 6–13% reductions in crime calls and halved disorder prevalence, demonstrating modest crime reductions and more pronounced disorder decreases.

Abstract

Many criminologists doubt that the dosage of uniformed police patrol causes any measurable difference in crime. This article reports a one-year randomized trial in Minneapolis of increases in patrol dosage at 55 of 110 crime “hot spots,” monitored by 7,542 hours of systematic observations. The experimental group received, on average, twice as much observed patrol presence, although the ratio displayed wide seasonal fluctuation. Reductions in total crime calls ranged from 6 percent to 13 percent. Observed disorder was only half as prevalent in experimental as in control hot spots. We conclude that substantial increases in police patrol presence can indeed cause modest reductions in crime and more impressive reductions in disorder within high crime locations.