Evidence-Based Policing Matrix
Jurisdiction – Lilley (2015)
Study Reference:
Location in the Matrix; Methodological Rigor; Outcome:
Jurisdiction; Focused; Highly Proactive; Rigorous; Mixed Effects.
What police practice or strategy was examined?
Weed and Seed programs are government-funded community improvement programs consisting of a law enforcement component (weeding) and a neighborhood restoration component (seeding), governed by a community steering committee. These programs can be further classified as including intensive law enforcement; community policing; prevention, intervention, and treatment; and/or neighborhood restoration. Weed and Seed programs typically target specific neighborhoods within funded jurisdictions. The current study sought to measure changes in crime rates correlated with Weed and Seed program implementation, identify which offenses were most affected by Weed and Seed programs, and examine the strength of those effects over a 15-year period (1990-2004).
How was the intervention evaluated?
This study examined 228 Weed and Seed jurisdictions as well as 250 randomly-selected comparison (non-intervention) jurisdictions without Weed and Seed programs. Researchers used a quasi-experimental design to compare changes in crime (murder, robbery, aggravated assault, rape, burglary, larceny, and vehicle theft) in the Weed and Seed and comparison jurisdictions over time while controlling for grant funding amounts, employment rates, income levels, and population demographics.
What were the key findings?
Results suggest that Weed and Seed produced statistically significant reductions in robbery, burglary, and vehicle theft. Effects were largest for robbery (up to 10%) and vehicle theft (6%). Results for murder, aggravated assault, larceny, and rape were less consistent or generally not statistically significant.
What were the implications for law enforcement?
Researchers attribute the success of Weed and Seed to a hot spots policing approach and community coordination. Weed and Seed programs narrowly target specific geographic areas and require coordination between law enforcement and other community stakeholders (including a community steering committee). This combination has largely contributed to their success; other programs have failed when they lack one or the other. Further, specific repeat offenders are often identified, targeted, and arrested through this approach as well.
Where can I find more information about this intervention, similar types of intervention, or related studies?