Evaluation of an FBI-led Gang Interdiction in South Central Los Angeles

• In Event: Evidence-Based Policing in the Western Region - Organized by the Western Society of Criminology

Abstract

This presentation reports on an outcome evaluation of the violence-reduction effects following an FBI-led gang takedown of the Rollin’ 30’s Harlem Crips in South Central Los Angeles. Analytically, the evaluation employed a Bayesian diffusion-regression state-space model designed to infer a causal effect of an intervention using data from a similar (non-targeted) gang area as a control. A statistically significant 22 percent reduction in violent crime was observed, a reduction that lasted at least nine months after the interdiction. Because so few FBI-led gang task force interventions have been studied for their crime reduction benefit at the neighborhood level, this presentation also discusses why this might be.

Author

• Jerry Ratcliffe, Temple University