By Nicholas Corsaro, Robin S. Engel, Tamara D. Herold,. Murat Yildirim

The gang and gun violence reduction project implemented in Las Vegas consisted of three components: hot spots deployment, focused deterrence, and place network investigations. This report focuses on the development, implementation, and evaluation of the hot spots strategy. The hot spots strategy involved the strategic deployment of additional saturation police patrols in high-crime locations. Specifically, to address violent street crime, the LVMPD engaged in a 6- month (Nov 1, 2018 to Apr 30, 2019) cluster randomized controlled trial (RCT) design of street segments receiving additional hot spots deployment (saturation patrols) and streets receiving patrol as usual (control segments). All potential street segments were identified from an analysis of persistent violent crime hot spots (where intensive police focus has been paid by the violent crime unit officers since January of 2018). Researchers stratified highest risk and independent segments within chronic and persistent hot spot locations. Specifically, 22 treatment segments and 22 control segments were selected to form the evaluation. No treatment segment was within a block or intersection of another treatment or control segment to reduce potential contamination of findings. Deployment of officers to the treatment hot spots occurred via calls for service every day, randomly for a total of two hours of exposure at each hot spot. Officers were instructed to remain at the hot spot for a total of 15 minutes, which is the optimum time for deployment to achieve effects as identified by researchers (Koper, 1995). When reaching the hot spot, officers were also randomly instructed to either stay in their vehicle with the lights on, or patrol the segment on foot. Interviews with arrestees have shown police presence is understood and alters criminal behaviors in patrolled areas (Golub et al., 2003). However, hot spot patrols such as walking are likely to go unnoticed by ordinary citizens (Weisburd, Hinkle, Fameaga, & Ready, 2011). Therefore, using both treatment types (stationary with lights and foot patrol) likely leads to increased awareness of police, thereby reducing criminal activity. The control treatment was for business to occur as usual at the control street segments. Center researchers conducted fidelity assessments during the project implementation phase, in order to ensure that the strategy was being implemented properly. These assessments indicated a strong adherence to the research design. Specifically, the research design called for a total of 2 hours of saturation patrol (in 15-minute increments) each day. Analysis of all hot spot patrols revealed that approximately 1.5 hours of additional patrol was observed each day for 90% of all hot spots. A total of 2 hours of additional patrol as observed for 55% of all hot spots. These findings demonstrate that the LVMPD carried out the hot spots strategy as designed.

Alexandria, VA: International Association of Chiefs of Police, 2019. 43p.