Kennedy, L. W., Caplan, J. M., & Piza, E. L. (2015). A multi-jurisdictional test of risk terrain modeling and place-based evaluation of environmental risk-based patrol deployment strategies. Rutgers Center on Public Security, Newark, NJ.
See also Caplan, J.M. and Kennedy, L.W. (2016). Risk Terrain Modeling: Crime Prediction and Risk Reduction. (University of California Press).
Location in the Matrix and Methodological Rigor:
Micro places, Focused, Proactive; Rigorous; Effective
What police practice or strategy was examined?
The quasi-experimental study evaluated police intervention strategies targeted at high-risk micro-level environments derived from risk terrain modeling (RTM) across 5 cities. Summarized here is the Kansas City, MO study, which focused on serious violence, which included all shooting incidents, aggravated assault (with a firearm), and street robbery (with and without a weapon). The RTM analysis yielded 15 significant risk factors associated with serious violence, including bus stops, weapon offending parolees and probationers, suspicious person calls for service, variety stores, liquor stores, hotels, fast food restaurants, drug markets, bars, halls, restaurants, convenience stores, grocery stores, foreclosures, and liquor licensed retailers. Using this information, the Kansas City Police Department designed its intervention to address nightclubs, suspicious persons with a weapon, weapon offending parolees and probationers, drug sales, packaged liquor stores, and liquor licensed retailers. Specific interventions included code enforcement, directed patrols, licensing and inspection checks, meet-and-greets with known offenders combined with social service referrals, CPTED inspections, and a few other tactics involving presence and premise or individual checks. The intervention lasted for over three months.
How was the intervention evaluated?
Control street units were identified using a Two Nearest Neighbors propensity score matching technique. Matching variables included whether the street unit intersected a high-risk street unit or a high-risk cell as identified by the RTM analysis, whether the unit was a segment or an intersection, the concentrated social disadvantage and racial heterogeneity in surrounding census block group, as well as pretest levels of crime and proactive police actions. Aggravated violence during the three-month intervention period and the three-month post-intervention period were compared to the figures during the same periods from the previous year in the treatment and control areas.
What were the key findings?
Aggravated violence decreased by 12% in the target area as compared to the control area, but the reduction did not achieve statistical significance. No significant effects were found at the micro-level in either the during- or post-intervention period. An additional evaluation that disaggregated various interventions suggests that pedestrian checks, directed patrol, and knock-and-talks have the greatest impact on reducing crime at micro-level places when sustained, and that longer-term crime reduction benefits at high-risk places are best achieved via building checks.
What were the implications for law enforcement?
The authors suggest that RTM enables the police to make decisions about where to allocate resources and what to do at high-risk places to suppress crime in the short- and long-term. While overall the intervention package did not produce significant reduction of aggravated violence during or post-intervention, some strategies such as pedestrian checks, directed patrol, and knock-and-talks conducted at micro risky places seems to be effective short-term, and others such as building checks can be effective in the long-run.
Where can I find more information about this intervention, similar types of intervention, or related studies?