Lawrence W. Sherman is Director of the Jerry Lee Center of Criminology at the University of Pennsylvania and Wolfson Professor of Criminology at the University of Cambridge, where he is a Fellow of Darwin College. As a pioneer of experimental criminology, he conducted the first random assignment field tests of the effects on crime of arrests, police raids, uniformed patrols, and (with Heather Strang) diversion from prosecution to police-led restorative justice conferences of offenders, their victims and their families. He has integrated the results of these and other experiments as “Defiance Theory,” predicting the conditions under which criminal sanctions increase crime rather than deterring it.
Sherman also discovered that street crimes are heavily skewed in space and time, with 3 percent of street addresses in any city generating more than half of all requests for emergency police responses. This finding led to police agencies around the world mapping their “hot spots” of crime. Sherman’s field experiment (with David Weisburd) shows that doubling police patrols in hot spots can reduce street crime by up to two-thirds without evidence of displacement.
Sherman’s Kansas City Gun Experiment, replicated in six other field tests, showed that police “stop and frisk” operations reduce homicides, shootings, and other gun crimes. His work (with Richard Berk and others) uses large samples of criminal histories to forecast which probationers and parolees are most likely to be charged with homicide or its attempt—an analytic approach that probation agencies are using to relocate their staff resources, and that the Pew Trust has recommended as a basis for criminal sentencing.
Sherman has served as president of both the American and International Societies of Criminology, as founding president of the Academy of Experimental Criminology, and as president of the American Academy of Political and Social Science from 2001 to 2005. He is author or co-author of Evidence-Based Crime Prevention; Policing Domestic Violence: Experiments and Dilemmas; Scandal and Reform: Controlling Police Corruption;Restorative Justice: The Evidence