To start a Campbell review, a title must be registered and approved by the appropriate Campbell review group. For information about the title registration and protocol and review steps, visit the Campbell website: http://www.campbellcollaboration.org/systematic_reviews/index.php
Submitted to the Coordinating Group of:
_X_ Crime and Justice
__ Education
__ Social Welfare
__ Other
Plans to co-register:
_X_ No
__ Cochrane __ Other __ Yes
__ Maybe
Instruction: Briefly address each item below. Provide enough precise information to allow us the ability to evaluate the scope of the review and its appropriateness for the Campbell Collaboration. Note the review proposal should not overlap with existing Campbell and Cochrane published reviews or registered reviews in progress.
TITLE OF THE REVIEW
The effects of increased police patrol on crime and disorder
BACKGROUND
Briefly describe and define the problem
Patrol is typically the largest function in police agencies around the world, and the majority of officers tend to be assigned to general service duties (Bayley, 1992).
Patrol officers generally spend their time responding to emergency calls for service from the public, deterring crime through their presence, and carrying out special assignments from supervisors. In recent years, it has become increasingly recognized that police agencies can have a beneficial impact on crime and disorder
(Lum, Koper, & Telep, 2011; National Research Council, 2004; Telep & Weisburd,
2012). Police patrol officers have likely played a major role in police efforts to effectively address crime as these officers make up a substantial portion of police resources and are on the front lines responding to crime and citizen concerns on a
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daily basis. An important question is the extent to which increased police presence and increased police patrols impact crime and disorder. If police can deter crime through their presence, does increasing the quantity of this presence help reduce crime and disorder? Being present, of course, is not the only activity patrol officers engage in, but it a major component of patrol and one that is important to examine systematically because agencies around the world devote such extensive resources to police patrol.
Increasing police presence can occur in a number of ways. One mainstay of policing since the 1930s has been random preventive patrol by automobile. Random patrol generally involves officers randomly driving around their beat in downtime between calls for service. The idea is to create a sense of omnipresence and to maximize deterrence by keeping offenders on their toes about when an officer will drive by next. Additionally, crime is expected to be deterred at the time officers are driving through (or sitting in) a particular area. Because crime is not randomly distributed across beats, but is instead highly concentrated (e.g. see Weisburd, Groff, & Yang,
2012), random preventive patrol has generally not been thought to be a very effective crime control tool (Telep & Weisburd, 2012). In the major study in this area, the Kanas City Preventive Patrol Experiment (Kelling et al., 1974), increasing
(or decreasing) levels of preventive patrol did not have a significant impact on crime or victimization.
Random preventive patrol is routinely dismissed as an ineffective strategy that police should not be using based largely on the results of this single study. As
Sherman and Weisburd (1995) note, the small sample of beats in the study created low statistical power, which made it difficult for the evaluation to discern a significant difference between the study groups even if one had existed (see also
Sherman, 1992). A more systematic examination of the impact of increasing patrol in beats or large geographic areas may thus provide a stronger answer to the question of “does random preventive patrol work?” than simply citing the Kansas
City study as the final answer.
In a recent review of systematic reviews in policing, Telep and Weisburd
(forthcoming) argued that while most police innovations in policing have been covered by an existing review, more traditional tactics in policing have received less attention. While these “standard model” tactics (Weisburd & Eck, 2004) such as random preventive patrol are generally seen as outdated, they continue to occupy a substantial portion of police time and resources and so more systematic inquiry into their effects would be worthwhile.
Increasing police presence is not limited to random patrols at the beat level.
Increasing preventive police patrols has also been an important component in a number of interventions at smaller units of geography than the police beat. The original hot spots policing experiment in Minneapolis (Sherman & Weisburd, 1995) focused on trying to increase patrol levels on high crime street blocks to three hours per day. More recently, the Sacramento Police Department used 15 minute stops by officers in a random order to increase police presence on high crime street segments
(Telep, Mitchell, & Weisburd, in press). Di Tella and Schargrodsky (2004) evaluated the impact of adding police officers to guard Jewish and Muslim buildings following a terrorist attack in Buenos Aires. Ratcliffe and colleagues (2011) evaluated the impact of using foot patrol to increase patrol levels in high crime areas in
Philadelphia. These hot spots or micro place interventions generally show stronger evidence of effectiveness, in part because police are maximizing their deterrent ability by focusing in on the highest crime places.
We recognize that many of these hot spots policing studies are also included in the hot spots policing systematic review by Braga, Papachristos, and Hureau (2012). We will focus though on only those hot spots studies focused entirely (or almost
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entirely) on increasing police presence. Any problem-oriented hot spots interventions, for example, will not be covered by our review and as a result, we do not expect the overlap between the two reviews to be substantial.
We suspect that most police interventions examining increased patrol and/or presence will focus on either the police beat or a micro place (e.g. hot spot) as the unit of analysis, although police could increase patrol levels at any unit of geography.
Our main requirements (discussed below) are that the increase in police presence be the focus of the intervention and that the evaluation focus on crime and disorder outcomes using a rigorous research design.
Briefly describe and define the population
Outline types of participant to be included and who is excluded, with thoughts given to aspects of the participants /target audience receiving the intervention.
E.g. age, gender, geographical location etc.
The population under consideration here will typically be geographic areas.
Criminal activity in these areas obviously involves individual offenders and victims, but we suspect that most studies will focus on aggregate crime in a particular geographic area (see below), and so our primary population of interest will be geographic units. These units can range in size from as small as an address or street segment to as large as an entire jurisdiction (although we believe that most interventions will focus on either hot spots or police beats).
Briefly describe and define the intervention
Define the intervention and specific comparisons to be made.
What is given, by whom and for how long?
Outline possible variations of the intervention.
What are the comparison conditions? E.g. no intervention, treatment as usual or alternative intervention.
The intervention will involve an increase in police patrol or presence in a specified geographic area. The exact length of the increase, the exact dosage of the increase, and the exact geographic area will vary by study, but in each study, the target geographic areas will receive an increase in police patrol/services compared to what these areas were receiving prior to the start of the intervention. The increased presence can be delivered in a number of different ways that will also vary by study.
The interventions could include increased visits by patrol officers or other units, the assignment of patrol officers to be in the target area constantly throughout the day, or the assignment of additional officers to patrol the target area. We will only include interventions that focus entirely (or almost entirely) on increasing police presence. We will not include police interventions that include a presence component but also focus primarily on other policing strategies such as problemoriented policing, focused deterrence approaches (“pulling levers”), or broken windows policing. We also will not include studies that focus exclusively on the relationship between department size and crime (e.g. see review by Marvell &
Moody, 1996). Increases in department size do not necessarily correspond to increases in police patrol, and so such studies would only be included if they assessed the impact of increasing police patrol on crime and met our methodological inclusion criteria.
The comparison condition will typically be “policing as usual.” This means the geographic areas not receiving extra police presence will generally continue to receive the same level of police services as before the intervention began. In some studies, the comparison condition may be the removal of some police services from a
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particular geographic area (e.g. the removal of preventive patrol in the reactive beats in the Kansas City study; Kelling et al., 1974)
Outcomes: What are the intended effects of the intervention?
What measurements will be used?
List primary and secondary outcomes (This will depend on the review and the field in question).
Eligible studies will focus primarily on crime and/or disorder as outcomes.
Outcomes will typically focus on total crime measured by either calls for service
(citizen calls to 911 for police assistance) or crime incidents. Outcomes may also focus on particular crime types (e.g. violent crime, property crime, Part I crime [FBI serious crime incidents], “soft” crime or disorder crime). While official data produced by police will be the primary outcome measure used, some studies may also use victimization survey data or observations of disorderly activity collected by research teams.
OBJECTIVES
The objective of this systematic review is to synthesize the extant empirical evidence
(published and unpublished) on the effects of increased police patrol on crime and disorder. Specifically, this review will seek to answer the following questions:
1.
How does increased police patrol affect crime and disorder?
2.
Do crime and disorder effects vary based on the type or intensity of the police intervention?
3.
Do crime and disorder effects vary based on the geographic unit of analysis for the police intervention (e.g. hot spots vs. police beats)?
METHODOLOGY
What types of studies designs are to be included and excluded?
Eligible studies would be randomized experimental designs or quasi-experimental studies with a comparison group.
Inclusion criteria:
1. The main intervention must be an instance of a police or law enforcement agency increasing police patrol or presence in a specified geographic area in an attempt to address crime and/or disorder. The geographic area is not restricted to a particular size and could include (but is not limited to) street segments, police beats, or neighborhoods. The police intervention must be limited to (or focused almost entirely on) increasing the amount of time officers are spending in the geographic area. For example, a hot spots intervention focused entirely on increasing officer time in the hot spots would be included, while a problem-oriented hot spots approach would not.
2. The intervention must be assessed using at least one crime or disorder related outcome. This could include measures related to total crime or disorder or total amount of a particular crime or disorder type.
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3. We will include randomized experiments or quasi-experiments with a comparison group that did not receive the intervention.
Exclusion criteria:
We will exclude qualitative studies or descriptive studies that do not include some measurable increased police patrol intervention.
Your method of synthesis:
We will use meta-analytic techniques (Lipsey & Wilson, 2001) for combining effect sizes when the number of studies and their composition allow. If appropriate, we will divide our meta-analysis by unit of analysis (e.g. hot spots/micro place studies vs. beat/neighborhood studies). We will also include a narrative review of all eligible studies.
SOURCES OF SUPPORT
Internal funding:
None
External funding:
Swedish National Council for Crime Prevention (Brå)
DECLARATIONS OF INTEREST
David Weisburd has previously been involved in multiple hot spots policing studies examining the effects of increased police presence on crime and disorder, including experimental interventions in Minneapolis (Sherman & Weisburd, 1995) and
Sacramento (Telep et al., in press).
Cody Telep has previously been involved in a hot spots policing study in Sacramento
(Telep et al., in press) examining the impact of increased police presence on calls for service and serious crime.
Maria Ttofi has not previously conducted any work on the effects of increased police presence on crime and disorder.
David Farrington has not previously conducted any work on the effects of increased police presence on crime and disorder.
REQUEST SUPPORT
Do you need support in any of these areas (methodology, statistics, systematic searches, field expertise, review manager etc?)
The project team has been involved in a number of Campbell Collaboration systematic reviews and we do not need any additional support.
We will use a statistical consultant if we need any assistance with calculating effect sizes in our study, should we decide to use meta-analysis. We will also consult with an information specialist to assist with our searches.
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AUTHOR(S) REVIEW TEAM
Include the complete name and address of reviewer(s) (can be changed later).This is the review team -- list the full names, affiliation and contact details of author’s to be cited on the final publication.
Lead reviewer:
The lead author is the person who develops and co-ordinates the review team, discusses and assigns roles for individual members of the review team, liaises with the editorial base and takes responsibility for the on-going updates of the review
Name: David Weisburd
Title: Distinguished Professor
Affiliation: Department of Criminology, Law and Society, George Mason University
Address: 4400 University Drive MS 6D12
City, State, Province or County: Fairfax, VA
Postal Code: 22030
Country: USA
Phone: 703.993.4079
Mobile: 301.318.2437
Email: dweisbur@gmu.edu
Co-author(s): (There should be at least one co-author)
Name: Cody Telep
Title: Research Associate
Affiliation: Department of Criminology, Law and Society, George Mason University
Address: 4400 University Drive MS 6D12
City, State, Province or County: Fairfax, VA
Postal Code: 22030
Country: USA
Phone: 703.993.6085
Mobile: 434.466.6326
Email: ctelep@gmu.edu
Name: Maria Ttofi
Title: University Lecturer in Psychological Criminology
Affiliation: Institute of Criminology, University of Cambridge
Address: Sidgwick Avenue
City, State, Province or County: Cambridge
Postal Code: CB3 9DA
Country: UK
Phone: +44 (0)1223 767186
Email: mt394@cam.ac.uk
Name: David Farrington
Title: Emeritus Professor of Psychological Criminology
Affiliation: Institute of Criminology, University of Cambridge
Address: Sidgwick Avenue
City, State, Province or County: Cambridge
Postal Code: CB3 9DA
Country: UK
Phone: +44(0)1223872555
Email: dpf1@cam.ac.uk
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ROLES AND RESPONSIBLIITIES
Please give brief description of content and methodological expertise within the review team. The recommended optimal review team composition includes at least one person on the review team who has content expertise, at least one person who has methodological expertise and at least one person who has statistical expertise. It is also recommended to have one person with information retrieval expertise.
Who is responsible for the below areas? Please list their names:
• Content: David Weisburd and Cody Telep
• Systematic review methods: David Weisburd, Cody Telep, Maria Ttofi, and David Farrington
• Statistical analysis: Maria Ttofi, David Farrington, and David Weisburd
• Information retrieval: Maria Ttofi and David Farrington with consultation from information specialist at the outset of the review
PRELIMINARY TIMEFRAME
Approximate date for submission of Draft Protocol (please note this should be no longer than six months after title approval. If the protocol is not submitted by then, the review area may be opened up for other reviewers):
We will submit the Draft Protocol within three months of Title approval. We plan to have the protocol ready for submission by June 2013.
REFERENCES
Bayley, D. H. (1992). Comparative organization of the police in English-speaking countries. In M. Tonry & N. Morris (eds.), Crime and Justice: A Review of
Research, vol. 15 (pp. 509–545). Chicago: University of Chicago Press.
Braga, A. A., Papachristos, A. V., & Hureau, D. M. (2012). Hot spots policing effects on crime. Campbell Systematic Reviews, 8(8).
Di Tella, R., & Schargrodsky, E. (2004). Do police reduce crime? Estimates using allocations of police forces after a terrorist attack. American Economic
Review, 94, 115–133.
Kelling, G. L., Pate, A. M., Dieckman, D., & Brown, C. (1974). The Kansas City
Preventive Patrol Experiment: Technical report. Washington, DC: Police
Foundation.
Lipsey, M. W., & Wilson, D. B. (2001). Practical meta-analysis. Thousand Oaks,
CA: Sage Publications.
Lum, C., Koper, C., & Telep, C. W. (2011). The Evidence-Based Policing Matrix.
Journal of Experimental Criminology, 7, 3–26.
Marvell, T. B., & Moody, C. E. (1996). Specification problems, police levels, and crime rates. Criminology, 34, 609–646.
7 The Campbell Collaboration | www.campbellcollaboration.org

Ratcliffe, J., Taniguchi, T., Groff, E. R., & Wood, J. D. (2011). The Philadelphia Foot
Patrol Experiment: A randomized controlled trial of police patrol effectiveness in violent crime hotspots. Criminology, 49, 795–831.
Sherman, L. W. (1992). Attacking crime: Police and crime control. In M. Tonry & N.
Morris (Eds.), Crime and Justice: A Review of Research, vol. 15 (pp. 159–230).
Chicago: University of Chicago Press.
Sherman, L. W., & Weisburd, D. (1995). General deterrent effects of police patrol in crime hot spots: A randomized controlled trial. Justice Quarterly, 12, 625–648.
Telep, C. W., & Weisburd, D. (Forthcoming). What has been learned from systematic reviews in policing? In D. P. Farrington & D. Weisburd (eds.), Systematic
reviews in criminology: What have we learned? New York: Springer.
Telep, C. W., & Weisburd, D. (2012). What is known about the effectiveness of police practices in reducing crime and disorder? Police Quarterly, 15, 331–357.
Telep, C. W., Mitchell, R. J., & Weisburd, D. (In press). How much time should the police spend at crime hot spots?: Answers from a police agency directed randomized field trial in Sacramento, California. Justice Quarterly.
Weisburd, D. & Eck. J. E. (2004). What can the police due to reduce crime, disorder and fear? Annals of the American Academy of Social and Political Sciences,
593, 42-65.
Weisburd, D., Groff, E. R., & Yang, S.-M. (2012). The criminology of place: Street
segments and our understanding of the crime problem. New York: Oxford
University Press.
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