Lawrence William Sherman

University of Cambridge | Cam · Institute of Criminology

This analysis employs a Bayesian framework to estimate the impact of a Cognitive-Behavioral Therapy (CBT) intervention on the recidivism of high-risk people under community supervision. The study relies on the reanalysis of experimental datal using a Bayesian logistic regression model. In doing so, new estimates of programmatic impact were produced...

Evidence-based policing (EBP) has become a key perspective for practitioners and researchers concerned with the future of policing. This volume provides both a review of where evidence-based policing stands today and a consideration of emerging trends and ideas likely to be important in the future. It includes comparative and international contribu...

Research Question Did the probability of a Metropolitan Police officer being dismissed in misconduct hearings in 2014–2018 differ between hearings chaired by Chief Officers in comparison to those chaired by Legally Qualified Chairs, overall and by ethnicity? Data We examined all 234 standard (excluding “special” or “accelerated”) misconduct hearin...

Research Question How have London’s racial and demographic disparities in homicide victimisation rates changed in 2 decades of the twenty-first century, with what implications for policing by consent? Data We collected Metropolitan Police Service homicide victimisation counts in London for each financial year (April through March) so far in the tw...

Purpose The purpose of this paper is to demonstrate a “maintenance pathway” for ensuring a low false negative rate in closing investigations unlikely to lead to a clearance (detection). Design/methodology/approach A randomised controlled experiment testing solvability factors for non-domestic cases of minor violence. Findings A random selection o...

Research Question Can racial equity in crime and policing be measured with the use of a Risk-Adjusted Disparity (RAD) Index of the degree to which policing across racial categories is “balanced” in its ratios of preventive police actions per 100 serious crimes committed against members of each racial category? Data Office of National Statistics (O...

Research Question How much racial disparity in trends of homicide victimisation rates in England and Wales is obscured by the failure of official statistics to report rates of death per 100,000 people at risk? Data We collected two decades of homicide victimisation counts in England and Wales, as broken out for each racial group identified by the...

The apparent paradox of guns and crime is that gun homicide rates have been dropping for three decades in the United States while the number of guns in circulation has been rising. Those trends form an apparent paradox because guns are so much more lethal, given an attack, than other weapons, and in general, the more weapons in a state, the higher...

Crime statistics require a radical transformation if they are to provide transparent information for the general public, as well as police operational decision-making. This statement provides a blueprint for such a transformation.

Objectives When offenders or victims are randomly assigned to receive experimental vs. current treatments, the external validity of results may depend on whether different treatments are delivered by similar kinds of treatment providers. When treatment providers volunteer to deliver innovative practices in an experiment, it is unclear whether outco...

The global problem of fatal encounters between police and citizens is a massive challenge for both public health and public safety. This volume focuses on a wide range of ideas and evidence about what might be done to save lives in police-citizen encounters, at least in the United States. I focus on three ideas that could make the most difference,...

The promise of evidence-based policing is to reduce harm with better research for targeting, testing, and tracking police actions. The problems of using evidence-based policing to reduce harm are found in the emotional dimensions of ethics and risk. These problems are most pronounced with fatal police shootings, where the risks of injury to America...

Objectives A central issue in experiments is protecting the integrity of causal identification from treatment spillover effects. The objective of this article is to demonstrate a bright line beyond which spillover of treatment renders experimental results misleading. We focus on a highly publicized recent test of police body cameras that violated t...

Research Question How did the use of diversion from prosecution and criminal sentencing change in Victoria, Australia, in the 10 years to 2016/2017, with what estimated effects on repeat offending? Data We tracked 1,163,113 criminal cases brought against both juveniles and adults by police in the state of Victoria, Australia, including 181,836 div...

Our understanding of causality and effect size in randomized field experiments is challenged by variations in levels of baseline treatment dosage in control groups across experiments testing similar treatments. The clearest design is to compare treated cases with no‐treatment controls in a sample that lacks any prior treatment at baseline. We appli...

Research Question How accurately can all recorded locations of 97 knife homicides in one year be forecast across all 4835 Lower Layer Super Output Areas (LSOAs) of London, based only upon all 3506 known locations of nonfatal knife injury assaults in the preceding year? Data All recorded “knife crimes” in the Metropolitan Police Service (MPS) area...

Research Question To what extent does citizen-reported crime in 500-meter square areas in Denmark, and arrests of individuals legally excluded from those areas for intimidating behavior, decline in the 3-month time periods in which their Exclusion Zone Orders (EZOs) are in effect, compared to the most recent 3-month period prior to the EZO? Data I...

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The U.S. President's Commission on Law Enforcement and Administration of Justice under President Johnson in 1967 called for a program of research that would support evidence‐based tracking, targeting, and testing of policing domestic “disputes.” During the past 50 years, the amount of research on domestic violence has grown. The findings from targe...

Can fatal shootings by American police be reduced? If so, what theoretical framework would be most useful in saving more lives? What research agenda would that framework suggest? The purpose of this review is to answer those three questions. It applies the system-accident framework (Perrow 1984) as a pathway to help police agencies reduce fatal pol...

Research QuestionAre selective decisions to dispatch police cars for interception of vehicles identified by ‘live alerts’ from fixed cameras using an Automatic Number Plate Recognition (ANPR) database associated with the highest levels of harm across all live alerts? DataThis study examined 70.3 million vehicle registration marks read by Fixed ANPR...

Research Question Can police substantially reduce targeted patrol time without increasing crime and disorder in crime hot spots already receiving high levels of patrol, at high-risk times, to find a more cost-effective ‘sweet spot’ level of patrol staffing for each hot spot? Data Merseyside Police measured police presence every 5 min via GPS locat...

Research Question Among Southampton-area males arrested for and admitting to low-risk intimate partner violence as a first domestic offence and receiving a conditional caution, did a randomly assigned requirement to attend (with four to seven other male offenders), two weekend day-long Cautioning and Relationship Abuse (CARA) workshops led by exper...

Research Question Does prior information retained in police intelligence records about an offender’s suicidal tendencies help to predict a future domestic homicide or attempted homicide? Data Records on 158,379 arrestees in 1997–2015 were examined for suicidal or self-harm warnings by date of entry and compared to 620 offenders identified in cases...

Research Question Does the severity or frequency of intimate partner violence or abuse reported to police increase over time, once a unique perpetrator-victim couple has come into contact with police in Thames Valley, UK? Data A total of 140,998 recent (non-historical) incidents of intimate partner violence or abuse reported to Thames Valley Polic...

Research QuestionCan integrated case management by a multi-agency partnership of the relations between offenders and victims with repeated incidents of intimate partner violence (IPV) reduce the frequency or severity of harm from that violence? DataThree batches of 60 IPV dyads were enrolled in a trial, with data collected on services delivered to...

Research Question What pathways to more accurate prediction of intimate partner homicide (IPH) can be found by reviewing two years of official Domestic Homicide Reviews in England and Wales? Data This study conducted a detailed review of investigative source material, police database information and the official independent author reviews of the 1...

\textit{Research Question}$ Does prior information retained in police intelligence records about an offender’s suicidal tendencies help to predict a future domestic homicide or attempted homicide? $\textit{Data}$ Records on 158,379 arrestees in 1997–2015 were examined for suicidal or selfharm warnings by date of entry and compared to 620 offenders...

College of Policing, Thames Valley Police

Research Question: Among Southampton-area males arrested for and admitting to low-risk intimate partner violence as a first domestic offence and receiving a conditional caution, did a randomly assigned requirement to attend (with 5 to 7 other male offenders), two weekend day-long Cautioning and Relationship Abuse (CARA) workshops led by experienced...

Research Question Is the vast majority of crime harm in one police force area over 1 year suffered by a small percent of all known victims, with many of those most-harmed victims suffering repeated and perhaps preventable crimes if more police resources were to be invested in them? Data All 30,244 crimes recorded as committed against all 25,831 pe...

Objectives To describe how social scientists, criminal justice practitioners, and administrative agencies collected administrative data to follow-up a criminological experiment after two decades. To make recommendations that will guide similar long-term follow-ups. Methods A case study approach describes the processes of and sociological benefits t...

Cognitive-behavioral therapy (CBT) is one of the most promising and widely used therapeutic approaches to reducing recidivism among criminal populations. Although many studies have evaluated CBT for this express purpose, few have done so in a community correctional environment. This article reports findings from a randomized field trial evaluating,...

Objectives To determine whether crime-reduction effects of increased police patrols in hot spots are dependent on the “hard” threat of immediate physical arrest, or whether “soft” patrols by civilian (but uniformed) police staff with few arrest powers and no weapons can also reduce crime. We also sought to assess whether the number of discrete patr...

The logic of simply summing crimes of all kind into a single total has long been challenged as misleading. All crimes are not created equal. Counting them as if they are fosters distortion of risk assessments, resource allocation, and accountability. To solve this problem, Sherman (2007, 2010, 2011 and 2013) has offered a general proposal to create...

Objectives We conducted and measured outcomes from the Jerry Lee Program of 12 randomized trials over two decades in Australia and the United Kingdom (UK), testing an identical method of restorative justice taught by the same trainers to hundreds of police officers and others who delivered it to 2231 offenders and 1179 victims in 1995–2004. The art...

This is the author accepted manuscript. It is currently under indefinite embargo pending publication by Hart.

Increasing numbers of police professionals have decided to practice evidence-based policing. Yet many of these “early adopters” encounter opposition from their colleagues. Advocates of evidence-based policing (EBP) increasingly ask whether, or how, an entire agency can be transformed at about the same time, rapidly creating a “tipping point” for “t...

Preventing the growth of political views justifying violence is central to global strategies for countering terrorism. In Western democracies, targeting resources on local ''hot spots'' of low confidence in the police is essential for making these strategies evidence based. This research explores the relationship between two kinds of evidence for t...

Preventing the growth of political views justifying violence is central to global strategies for countering terrorism. In Western democracies, targeting resources on local “hot spots” of low confidence in the police is essential for making these strategies evidence based. This research explores the relationship between two kinds of evidence for tar...

In policing, quality of implementation—not just whether a policy is implemented, but how it is implemented—often means the difference between achieving the desired outcomes or not. Police leaders can respond to tracking evidence that shows poor quality of implementation by either improving officer compliance with policy, improving the policy itself...

Objectives To examine the impact of face-to-face restorative justice conference (RJC) meetings led by police officers between crime victims and their offenders on victims’ post-traumatic stress symptoms. Methods Two trials conducted in London randomly assigned burglary or robbery cases with consenting victims and offenders to either a face-to-fa...

There is a widely repeated claim that victims of domestic abuse suffer an average of 35 incidents prior to someone calling the police. This claim is often made without reference to any evidence. When evidence has been cited, the citations often refer to studies that contain no such evidence. After extensive inquiry, the only evidence we can find fo...

In late 2013, Trinidad and Tobago Police Service (TTPS) conducted the first randomized experiment ever to test a hot spots patrol strategy (HSPS) across large areas, as distinct from testing extra patrols one hot spot at a time. The HSPS experiment required, and helped to refine, a formal theory of both the causes and effects of directed patrols in...

Objectives We explored death rates from all causes among victims of misdemeanor domestic violence 23 years after random assignment of their abusers to arrests vs. warnings. Methods We gathered state and national death data on all 1,125 victims (89 % female; 70 % African-American; mean age = 30) enrolled by Milwaukee Police in 1987–88, after 98 % tr...

Objectives This paper synthesizes the effects on repeat offending reported in ten eligible randomized trials of face-to-face restorative justice conferences (RJCs) between crime victims, their accused or convicted offenders, and their respective kin and communities. Methods After an exhaustive search strategy that examined 519 studies that could ha...

Objective To test for any long-term effects on the death rates of domestic assault suspects due to arresting them versus warning them at the scene. Methods The Milwaukee Domestic Violence Experiment (MilDVE) employed a randomized experimental design with over 98 % treatment as assigned. In 1987–88, 1,200 cases with 1,128 suspects were randomly ass...

This Campbell systematic review examines the effectiveness of face‐to‐face restorative justice conferences (‘RJCs’) on repeat offending and victim satisfaction. The systematic review includes 10 studies. The average effect of the ten studies indicated that face‐to‐face RJCs resulted in offenders committing significantly less crime than their counte...

In proposing a CONSORT extension for tests of interventions in five different fields, Grant et al. (this volume) spotlight several important problems. Rather than beginning with their proposed solution, this comment begins by offering a viewpoint on the key problem to be solved, and then considers what kind of CONSORT extension could provide the be...

Evidence-based policing is a method of making decisions about “what works” in policing: which practices and strategies accomplish police missions most cost-effectively. In contrast to basing decisions on theory, assumptions, tradition, or convention, an evidence-based approach continuously tests hypotheses with empirical research findings. While re...

The reintegrative shaming experiments (RISE) were conducted in Canberra, Australia, between 1995 and 2000. RISE compared the effects of standard court proceedings to restorative justice (RJ)-focused diversionary conferences (DCs) with juvenile, young adult, and adult offenders who had been arrested for personal property, shoplifting, violent, or dr...

Objectives This note describes a low-cost online portal called “the Cambridge Randomizer”, which enables treatment providers to conduct random assignment themselves, while the researcher still maintains control over the entire process and the integrity of the allocation process. Methods Discussion of the advantages and disadvantages of the tool; c...

This chapter discusses experimental criminology. It begins by describing two different models that have greatly advanced field experiments on crime and justice in the last few decades (center to periphery and periphery to center), but owing to political realities have lost some of their influence. It argues that experimental criminology remains a v...

This article takes a look at the conclusions from twenty years of restorative justice (RJ) innovations and their status as of 2011. The discussion is primarily concerned with the face-to-face restorative justice conference (RJC), which combines offenders, their victims, and their respective families and communities, in order to decide what the offe...

This article examines the growing gap between evidence and practice in democratic policing, primarily in the English-speaking nations (especially the United States, the United Kingdom, and Australia). Section I describes the framework for evidence-based knowledge about policing for crime control, with recent advances in some of the tools for genera...

This chapter is concerned with Paul Rock's work on the criminology of law-making. It highlights the role of the organizational weapon of victim advocacy organizations, asking whether they are central to the making of laws about victims and whether advocacy or lobbying groups are generally a necessary condition for law-making about crime. It also ap...

Criminology was invented as a new way of reducing human suffering. If an invention is a 'new design for doing something', the 'something' criminology was designed for was less crime and injustice. Criminology has been most successful in producing those results when it has focused on inventing and testing new laws, institutions, and social practices...

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 (Campbell and Stanley 1963; Cook and Campbell 1979). While the expe...

The Philadelphia Low-Intensity Community Supervision Experiment provides evidence on the effects of lowering the intensity of community supervision with low-risk offenders in an urban, US county community corrections agency. Using a random forests forecasting model for serious crime based on Berk et al. Journal of the Royal Statistical Society, Ser...

Eisner (Journal of Experimental Criminology, this issue, 2009) suggests that developer-led evaluations often make programs look better than independent evaluations do because the former suffer systematic biases in favor of prevention success. Yet, his proposed remedies suffer their own systematic bias, constituting a ‘one-tailed’ test of bias in on...

Evidence and liberty are two great ideas in British history. One consequence of both ideas is experimental criminology, which applies research designs developed in Britain to matters of liberty affecting the entire world. The promise of experimental criminology is to generate better evidence about how to increase liberty. The crucial challenge to e...

Forecasts of future dangerousness are often used to inform the sentencing decisions of convicted offenders. For individuals who are sentenced to probation or paroled to community supervision, such forecasts affect the conditions under which they are to be supervised. The statistical criterion for these forecasts is commonly called recidivism, which...

The promise of experimental criminology is finding ways to reduce harm from crime and injustice. The problem of experimental criminology is that so few experiments produce evidence of big effects from the interventions they test. One solution to this problem may be concentrating scarce resources for experiments on the “power few:” the small percent...

Advocates of restorative justice (RJ) hypothesize that the diversion of criminal cases to RJ conferences should be more effective in lowering the rate of reoffending than traditional prosecution in court processing because the conferences more effectively engage the psychological mechanisms of reintegrative shaming and procedural justice. This stud...

The National Research Council (NRC) Report on Improving Evaluation of Anticrime Programs raises a fundamental question about the mission of evaluation research. The implicit premise of the report is that the mission of evaluation is to answer questions about programs developed by others; in short, to test anti-crime programs. In contrast, the missi...

In “Crime and Juvenile Delinquency,” Lawrence W. Sherman, a professor at the University of Pennsylvania’s Department of Sociology, describes how changes in criminal and other dysfunctional behaviors could be measured. He relies on data from the National Crime Victimization Survey and the Uniform Crime Reporting System. Sherman describes how crimina...

One major goal of face-to-face restorative justice (RJ) is to help heal the psychological harm suffered by crime victims (Braithwaite, 2002). Substantial evidence from randomized controlled trials (RCTs) has shown that this can be accomplished (Strang, 2002) and more trials are underway (Sherman & Strang, 2004). These outcomes are even more clearly...

This article responds to John Angell's (1971) proposal to abolish police middle management. With use of the data from a seven-city study of team policing (Sherman et al., 1973) and Tannenbaum's (1968) framework of control in organizations, the past obstructions and potential uses of middle management to police change are discussed. Rather than abol...

What do we know about the effects of restorative justice (RJ) on victimization? The answer to that question depends on how we know what we think we know. This chapter answers a traditional question in crime prevention research with a non-traditional method, the systematic review. The aim of this chapter is to describe our conclusions about the effe...

The growing use of restorative justice provides a major opportunity for experimental criminology and evidence-based policy. Face-to-face meetings led by police officers between crime victims and their offenders are predicted to reduce the harm to victims caused by the crime. This prediction is derived not only from the social movement for restorati...

After a useful beginning in the eighteenth-century Enlightenment as both an experimental and analytic social science, criminology sank into two centuries of torpor. Its resurrection in the late twentieth century crime wave successfully returned criminology to the forefront of discovering useful, if not always used, facts about prevailing crime patt...

Randomized experiments that examine the effectiveness of criminal sanctions suggest that they may increase crime, decrease crime, or have no effect. To better understand these disparate findings, we need to more carefully examine the types of sanctions being tested, in terms of their severity, certainty, and celerity (speed), and the types of offen...

The evidence of arbitrary and capricious exercise of discretion in arrests can persuade police that a randomized experiment is ethical and useful.