This systematic literature review and meta-analysis of evaluation studies on street gang control strategies focused on articles and reports from multiple bibliographic databases. The database search resulted in a total of 2,060 hits. Of the 297 studies that were examined, only 38 were retained for the systematic review after all screening procedures and inclusion criteria were applied. This list of studies was classified into a typology of five broad categories of street gang control strategies, including: 1) prevention, 2) gang activity regulation, 3) justice system based intervention, 4) comprehensive, and 5) holistic.
A quantitative synthesis of program outcomes could not be undertaken because of the difficulty in pooling together studies that were incommensurate; it was considered substantively meaningless to produce a summary effect. Instead, a systematic review was undertaken. The systematic review of street gang control strategy evaluation studies revealed that findings in regard to effectiveness were not encouraging, especially for studies evaluating general prevention, and gang membership prevention programs. Overall, it was found that the more specific the targeted population, the more evaluations tended to show signs of effectiveness. Gang activity suppression programs was the only category of approaches in which evaluations found consistent positive outcomes. It was also found that the more chronic the gang problem, the more effective gang activity suppression approaches. None of the evaluations of comprehensive and holistic programs produced any strong evidence in terms of effectiveness. Probably the most surprising finding in this report concerned the Spergel Model, which was shown to be ineffective mostly due to implementation fidelity. Three major recommendations concerning gang control strategies were discussed: the need for consistent independent evaluations applying scientific methodologies; programs should be built on empirical research findings and not intuition or common sense; and evaluations should be an integral part of the implementation process of a program.