Experimental Criminology @ Cambridge

Professor Sherman "Less Prison, More Policing"
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Professor Sherman "Professional Policing". The Benjamin Franklin Award 2011.
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Watch the Evidence-Based Policing Seminar at the French Academie des Sciences

Welcome to the Jerry Lee Centre of Experimental Criminology.The Jerry Lee Centre of Experimental Criminology at the Cambridge University Institute of Criminology conducts and synthesizes randomized controlled trials of policing, criminal justice and crime prevention programmes, in tandem with training doctoral and post-doctoral students the methods and practices of experiments in crime and justice. The Centre's mission is to produce better evidence for advancing human liberty. Founded in 2007 with support from the Jerry Lee Foundation of Philadelphia, the Cambridge Centre works closely with the Jerry Lee Center of Criminology at the University of Pennsylvania. In collaboration with the Australian National University, these centres jointly operate the Jerry Lee Program of Randomized Controlled Trials in Restorative Justice, a series of 12 field experiments involving over 3,000 crime victims and offenders. The Centre is also undertaking new experiments on a variety of innovations for preventing serious crime, including homicide.

What Is Experimental Criminology?

Experimental criminology is the use of advanced experimental methods to answer key questions about the causes and responses to crime.

  • How much crime does prison prevent--or cause--for different kinds of offenders?
  • Does visible police patrol prevent crime everywhere or just in certain locations? What is the best way for societies to prevent crime from an early age?
  • How can murder beprevented among high-risk groups of young men?

For a 6-minute video presentation by Cambridge University describing one such experiment, please see this
Cambridge Ideas Video.
These and other urgent questionscan be answered most clearly by the use of a research design called the "randomized controlled trial." This method takes large samples of people--or places, or schools, prisons, police beats or other units of analysis--who might become, or have already been, involved in crimes, eitheras victims or offenders. It then uses a statistical formula to select a portion of them forone treatment, and (with equal likelihood) another portion to receive a different treatment. Any difference,on average,in the two groupsin their subsequent rates of crime or other dimensions of life can then be interpreted as having been caused by the randomly assigned difference in thetreatment. All other differences, on average, between thetwo groups can usually be ruledout as potential causes of the difference in outcome. That is because with large enough samples, random assignment usually assures that there will be no other differences between the two groups except the treatment being tested.

Why Cambridge?

Experimental criminologyis a rapidly growing field, with increasing influence on public policy decisions.It has already shown how to prevent millions of violent crimes, as well asunnecessarypre-trial detentionof millions of people. These reasons alone make it appropriate to locate the world's first Centre of Experimental Criminology at Cambridge University, which has won moreNobel Prizesthan any other university in the world.For like experimental medicine,this branch of criminology uses a scientific method that was invented by aCambridge graduate,Sir Ronald Aylmer Fisher, whose theoretical work on experimental methods revolutionized the study of cause and effect.In his time at Cambridge Fisher won the undergraduate mathematics prizeandlater spent 17years as Professor of Genetics.Among his many ideas was the central insight that random assignment of a consistent action across some but not all of a large population could "hold constant"the other factors that could affect anysubsequent outcomes.
In 1959 Cambridgealsoestablished the first Institute of Criminology in the English-speaking world, with close links to the UK government and its need for policy-relevant research. Established in part with funds from the Wolfson Foundation at the request of HomeSecretary RA Butler, the Cambridge Institute of Criminology has engagedequally with theoretical and applied questions ofthe causes and prevention of crime throughout its distinguished history. These questions were of great interest to the Institute's founder,Sir Leon Radzinowicz, as well as to its long-term Director Sir Anthony Bottoms and its current Director Professor Friedrich Losel . They have also been of particular interest to the Institute's polymath of all branches ofcriminology,Professor David Farrington, who co-founded the Academy of Experimental Criminology in 1998 and servedas its President (2001-2004).
For these and other reasons, theJerry LeeFoundationdecided in 2006 to offer to help found the first university centre devoted solely to the advancement of experimental criminology. Withthe Lee Foundation'sinitial pledge to fund a programme of pre-doctoral and post-doctoral "Jerry Lee Scholars," the University agreed to have the Jerry LeeCentre of Criminology established in the Law Faculty's Institute of Criminology in 2007. In that same year Lawrence Sherman, the University's fourth Wolfson Professor of Criminology, was appointed the first Director of the Jerry Lee Centre.
This appointment alsobenchmarked ten years ofa continuing collaboration between Sherman and the Foundation'sPresident,Jerry Lee, whohas championed social science research in business and government for decades.
Their collaboration includes contributions to the founding of the Stockholm Prize in Criminology , theJerry LeeCentre of Criminology and theDepartment of Criminologyat the University of Pennsylvania, theDivision of Experimental Criminology of the American Society of Criminology,and other initiatives for advancing the institutional development ofcriminology. This includesthe largest programme of multiple randomized trials of a single crime prevention startegy ever conducted in experimental criminology, theJerry LeeProgram of Randomized Controlled Trials in Restorative Justice,a series of 12 field experiments involving over 3,000 crime victims and offenders. A recent independent evaluation of seven of these Jerry Lee Program experiments conducted by Professor Joanna Shapland and her team found an overall 27% reduction in the frequency of reconvictionsof offenders two years after random assignment to restorative justice meetings, compared to similar consenting offenders who werechosen for the control group.

What Does The Centre Do?

The Jerry Lee Centre for Experimental Criminology at Cambridge has two primary tasks. One is to conduct research, with emphasis uponprimary and secondary analyses of randomized controlled experiments in crime and justice. Its second task is to select and train an outstanding cadre of experimental criminologists for the future.


The Centre's research program is currently focused in threemajor areas. One is restorative justice, through the multi-national efforts noted above. This includes its responsibility for the Campbell Collaboration's systematic review of the effects of face-to-face restorative justice on crime victims and offenders. A second area of research is homicide prediction and prevention. This includes various initiatives with UK police and health agencies, as well as with Philadelphia's Adult Probation and ParoleDepartment.The first paper of thisproject on forecasting homicide was recently published by the Journal of the Royal Statistical Society (Series A). The third and most rapidly-growing area is the conduct of field experiments in collaboration with UK police agencies, led by the Greater Manchester Police in its TEST (Tactical Experiments and Strategic Testing Program)


The Centre will carry out its training mission by recruitingand training highly effective people to design key experiments in crime and justice, to obtain funding and agency partners for conductingthe experiments, and to analyze and report the results of these experiments with integrity and insight. These tasks go well beyond the standard skill-set found in observational or analytic criminology, and are especially dependent on the interpersonaland emotional intelligence of the scholar.People with excellent academic achievementsareespecially welcome to apply for the fully-funded Jerry LeeScholarships to pursue pre- and post-doctoral training in experimental criminology. Those who show, in addition to excellence at writing and thinking,the best evidence ofability to create and lead research projects willbe the most competitive.
The Jerry LeeScholars Program will accept applications for pre- and post-doctoral study at Cambridge starting in 2010. Anyone interested inapplying to the program can gather further information from the Centre Director,Professor Lawrence Sherman.

Our Centre, founded in 2007, is the first of its kind. Please meet the team:

Director, Institute of Criminology, Cambridge, Director, Jerry Lee Centre for Experimental Criminology and Founding President, Academy of Experimental Criminology

Honrorary Research Fellow at the Institute of Criminology, Cambridge, and Fellow, Academy of Experimental Criminology
Professor of Psychological Criminology and Past President, Academy of Experimental Criminology

Professor of Comparative & Developmental Criminology
Deputy Director, Police Executive Programme and Deputy Director, Jerry Lee Centre for Experimental Criminology
Jerry Lee Fellow in Experimental Criminology and Lecturer of Evidence Based Policing

Ph.D. Candidate, Project Director of Crime Harm Experiments and Former Chief Constable, Thames Valley & NPIA

We are currently engaged in several vital projects to advance our field, including:


REX-COST is an acronym of Registry of EXperiments in COrrections Strategy and Tactics

All submissions for this regsitry should be sent, in CRIM-PORT format, to Dr Heather

Registry of Experiments

  1. Criminological Protocol for Operating Randomized Trials, Ruback 2012
  2. Do offenders discover the harm of their offences? A multi-site randomised controlled trial evaluation of the Sycamore Tree Programme, WIlson 2013


REX-POST is an acronym of Registry of EXperiments in POlicing Strategy and Tactics

All submissions for this regsitry should be sent, in CRIM-PORT format, to Dr Heather

Registry of Experiments

  1. West Midlands Police
  2. Operation Beck
  3. Operation Turning Point
  4. The Salt Lake City Court-Mandated Restorative Justice Treatment For Domestic Batterers Experiment - Part I
  5. The Rialto Police Department Wearable Cameras Experiment

Armed Police

Experimental criminology is scientific knowledge about crime and justice discovered from random assignment of different conditions in large field tests. This method is the preferred way to estimate the average effects of one variable on another, holding all other variables constant While the experimental method is not intended to answer all research questions in criminology, it can be used far more often than most criminologists assume. Opportunities are particularly promising in partnership with criminal justice agencies.

Police vans

The highest and best use of experimental criminology is to develop and test theoretically coherent ideas about reducing harm from crime, rather than just €œevaluating€ existing or even new government programs. Testing key ideas, in turn, can help to accumulate an integrated body of grounded theory in which experimental evidence plays a crucial role. When properly executed, randomized field experiments provide the ideal tests of theories about both the prevention and causation of crime.

The many advantages of experimental methods help explain why this branch of criminology is growing rapidly. Just since 2005, the field has seen its first journal established (Journal of Experimental Criminology), its own separate Division of Experimental Criminology within the American Society of Criminology, and the first University centre dedicated solely to this field: the sponsor of this page, the Jerry Lee Centre for Experimental Criminology at Cambridge University. All these institutions are dedicated to making the most of the better knowledge experiments can bring.

Yet these advantages depend entirely on the capability of the experimenters to insure success in achieving the many necessary elements of an unbiased comparison. Many, if not most, randomized field experiments in criminology suffer flaws that could have been avoided with better planning. The lack of such planning, in turn, may be due to the scant attention paid to field experiments in research methods texts and courses. Even skilled, senior researchers can make basic mistakes when conducting field experiments, since experiments require a very different set of skills and methods than the €œnormal science€ of observational criminology.

This web page is intended to help foster better experiments in criminology, in three ways:

  1. Providing a format for experimental planning, called protocols.
  2. Providing registries for criminology experiments, where protocols can be transparent and credible.
  3. Providing links to people doing experimental criminology, to foster more communication.

For further information about experiments in criminology, contact Dr. Barak Ariel at Cambridge,

YouTube video of Professor Sherman's 'Crime Hot Spots' chat

For other global institutions in experimental criminology, please click on the following links:

Professor Sherman in the Telegraph: The magic bullet that could solve our prison problem.

Professor Sherman's new book, Experimental Criminology, was published in February 2012. To purchase the book, please click HERE or on the image of the book above.

Professor Sherman is also the Director of the Police Executive Programme.