The collection of papers in this Special Issue came about as a result of the most significant funding award to date dedicated to obtaining a broad perspective of “what works” in the field of policing. In 2009, the National Policing Improvement Agency (NPIA) in the United Kingdom, under the leadership of former Thames Valley Police Chief Constable Peter Neyroud, provided over US$600,000 to the Campbell Collaboration Crime and Justice Group (CCJG), via the Center for Evidence-Based Crime Policy at George Mason University where CCJG’s editorial team is based, to develop a portfolio of systematic reviews on policing topics. In total, 11 systematic searches and reviews were completed and peer reviewed under this program between 2009 and 2013.

The full set of reviews is discussed in detail in Telep and Weisburd, this issue.

This Special Issue contains a selection of these reviews not published elsewhere, as well as several papers on lessons learned from the funded projects and areas for futur ...