In 2012, the St. Louis Metropolitan Police Department (SLMPD) implemented an experiment to assess the impact of different hot spots-policing tactics (directed patrol and self-initiated enforcement) on firearm violence. The experiment was implemented as part of a “Public Safety Partnership,” which included the SLMPD, the mayor’s office, and researchers at the University of Missouri, St. Louis. The SLMPD’s Crime Analysis Unit (CAU), alongside university researchers, developed the experiment, which was designed to last for 9 months.
Although hot spots policing, in general, includes the increase of police presence in an area where crime typically occurs, there are different tactics that can be used by the officers to specifically address crime. Therefore, the overall goal of this experiment was to investigate the relative effectiveness of two different tactics: directed patrol and self-initiated enforcement.
The CAU selected 46 geographic areas in St. Louis with the highest amount and concentration of firearm violence and robberies occurring over several months during the year prior to the experiment. Firearm violence was determined by counts of homicides and nondomestic aggravated assaults committed with a firearm. From this list, the CAU selected four areas within each of the eight districts with the highest amount and concentration of firearm violence.
Officers who were assigned to directed patrol were instructed to patrol slowly through the hot spots area and avoid engaging in self-initiated contact, unless a crime was in progress, or the safety of a citizen or fellow officer was in jeopardy.
Conversely, officers who were assigned to self-initiated enforcement tactics were also instructed to patrol slowly through the hot spots area, but were also told to engage in forms of self-initiated activity. Self-initiated activity was defined as arrest, pedestrian checks, building checks, occupied vehicle checks, unoccupied vehicle checks, foot patrol, and problem solving. The experiment was limited to evening shifts (3:00 – 11:00 p.m.) and overnight shifts (11:00 p.m. – 7:00 a.m.), when the frequency of firearm violence was the greatest.