U.S. Department Of Justice MTE N T OFJ P A R USTI D E CE .

Use of Force by Policeaccomplish their goals. The kinds of policeactions that most arouse the public’s concerns—such as fatal shootings, severebeatings with fists or batons that lead to hospitalization, and choke holds that cause unconsciousness or even death—are not typicalof situations in which police use force.When injuries occur as a result of the useof force, they are likely to be minor. In onestudy (chapter 5), researchers found thatthe most common injury to a suspect was abruise or abrasion (48 percent).Another research finding that can be accepted with substantial confidence is thatuse of force typically occurs when police aretrying to make an arrest and the suspect isresisting. This conclusion is based on fourtypes of data: arrest statistics, surveys of police officers, observations of police behavior,and reports by the public about their encounters with police.The foregoing findings leave open the issueof excessive force because issues of proportionality are not clearly addressed. Researchfindings suggest, however, that many debates over excessive force will fall into grayareas where it is difficult to decide whetheran officer acted properly, given credible evidence that use of force was necessary.Known with modest confidenceRegarding what is known with modest confidence about police use of force, chapter 1identifies three conclusions suggested byresearch data: Use of force appears to be unrelated to anofficer’s personal characteristics, such asage, gender, and ethnicity. This conclusionshould be accepted with caution, however.Additional verification is needed. Use of force is more likely to occur whenpolice are dealing with persons under theinfluence of alcohol or drugs or with mentally ill individuals. Research findings inthis area are inconsistent, however. Further investigation, with an emphasis onimplications for training, could lead to areduction in the risk of force and injuryfor both police officers and civilians. A small proportion of officers are disproportionately involved in use-of-forceincidents. More research is needed.About this reportThis report is one of a series of use-of-forcepublications (see Bibliography, page 75)generated by research supported by theNational Institute of Justice or Bureau ofJustice Statistics. The data and findingsherein contribute to a better understandingof the extent and nature of police use offorce and of the circumstances under whichsuch force is applied.A major objective of chapter 1 is to providean overview of what is known (and notknown) about police use of force andthereby help readers put the issue in perspective. The next two chapters are updatesof two national projects. One is designed tocollect data on police-public contacts, including those involving police use of force, froma nationally representative sample of per-viiisons age 12 or older. The other seeks toencourage as many local law enforcementagencies as possible to submit voluntarilyand anonymously use-of-force data to acentral database for analysis.Chapters 4 and 5 focus on the local level.They present use-of-force findings basedon data acquired from nine police agencies.The final chapter looks ahead by proposinga research agenda on police use of force,with special attention given to issues ofexcessive force.Thus, this report begins with an overviewof what is known about police use of force,proceeds to outline what is being learned,and concludes with a proposed plan forfuture research.

Executive SummaryAmong what is not knownAs stated in chapter 1: “The incidence ofwrongful use of force by police is unknown.Research is critically needed to determinereliably, validly, and precisely how oftentransgressions of use-of-force powers occur.”Researchers and practitioners both tend topresuppose that the incidence of excessiveforce by police is very low. If use of force isuncommon, and civilian complaints are infrequent, and civilian injuries are few, thenexcessive force by police must be rare. Thatconclusion may indeed be correct, but to theextent that it hinges on official police statistics, it is open to serious challenge.lead to excessive force by police seem obvious, or appear to be a matter of commonsense, a great need for systematic research in this area exists. Influences of situational characteristicson police use of force and the transactional nature of these events are largelyunknown. For example, little is knownbeyond research indicating that situationsmost likely to involve police use of forceare interpersonal disturbance and violentpersonal crime, and situations when suspects attempt to flee or physically resistarrest. Those findings, however, do notaddress the transactional, or step-by-stepunfolding, of police-public encounters. Wassuspect resistance the result of police useof force, or did police use force after experiencing suspect resistance?Current indicators of excessive force, such ascivilian complaints and civil lawsuits, are allcritically flawed. The difficulties in measuring excessive force with complaint andlawsuit records have led academics andpractitioners to redirect their attention toall use-of-force incidents. Theoretically, understanding all use-of-force incidents helpsput wrongful use of force in perspective.Updates on Two National ProjectsAs one example of how understanding alluse-of-force incidents can help put excessiveforce in perspective, the study of 7,512 adultcustody arrests (chapter 4) makes thisobservation:The BJS survey“ . . . most arrests involve no force, excessiveor otherwise. When force is used, it typicallyinvolves less severe forms of tactics andweapon use. These findings provide a contextfor understanding excessive force, which weknow can involve low-level acts of force . . .as well as the acts of force that result inphysical injury or death of civilians. Arreststhat involve no force, however, cannot involve excessive force and arrests that involvelow levels of force are less likely to involveexcessive force.”Additional gaps in use-of-force knowledgeinclude the following: The impact of differences in police organizations, including administrative policies,hiring, training, discipline, and use oftechnology, on excessive force is unknown.Although many conditions that arguablyIn 1996, the Bureau of Justice Statistics(BJS) and the International Association ofChiefs of Police (IACP) initiated projects involving collection of data encompassing police use of force. Both are currently ongoing.To learn more about police use of force requires an understanding of the reasons forand the results of police-public encounters.As a step toward developing that understanding, BJS supplemented the NationalCrime Victimization Survey with a pilot testof its Police-Public Contact Survey (PPCS) in1996 (chapter 2).“NCVS is based on interviews conducted with anationally representativesample of U.S. households and has become ahighly useful platform fortesting new questionnaires and periodicallyimplementing supplements.” —Greenfeld, etal., page 15 of this report.Among the findings was a preliminaryestimate that about 1 percent of people reporting contacts with police indicated thatofficers used or threatened force. In themajority of those instances, respondents saidthat their own actions, such as threateningpolice, may have provoked officers.In July 1999, a second test of PPCS wasfielded to a much larger sample than thatused in the 1996 pilot test. In addition, BJSanticipates adding items to its periodic surveys conducted among nationally representative samples of those confined in local jailsix

Use of Force by Policeand prisoners held by State and Federalauthorities. The new survey items wouldprovide, for the first time, information aboutrespondents’ interactions, including use offorce, with police during the arrest precedingincarceration.The IACP database project“.IACP designed theproject from the outset toreflect operational realities of modern, street-levellaw enforcement, including the very meaning of‘police use of force,’ defined as the amount offorce required by police tocompel compliance by anunwilling subject.”—Henriquez, page 20 ofthis report.Initiated in 1996, the IACP database projectis designed to collect use-of-force informationfrom law enforcement agencies across theNation (chapter 3). To promote accurate reporting and overcome potential reluctanceof agencies to participate, IACP decided thatprovision of data would be both voluntaryand anonymous.Collected data pertain to reported use offorce stemming from police responses to callsfor service, whether or not those responsesresulted in arrests. About 150 agencies areexpected to contribute data for the 1998–99data year. Among preliminary findings: Based on 1995 data reported by 110 agencies, the police use-of-force rate was 4.19per 10,000 responded-to calls for service,or 0.0419 percent. Based on data reported for 1996–97, 87percent of 62,411 use-of-force incidentsinvolved officers using physical force. Officers used chemical force in 7 percent ofthe incidents, firearms in about 5 percent. Based on available data for 1996–97, about10 percent of 2,479 officers using force sustained injuries, less than 1 percent serious.About 38 percent of subjects were injureddue to police use of force, with 1.5 percentsustaining major injuries.Because the data are not yet nationallyrepresentative, conclusions about nationaluse-of-force trends should not be attempted.the force factor, a measure of the level offorce used by officers relative to the level ofresistance by suspects.Study on the amount of force used insix jurisdictionsThe six-jurisdiction study (chapter 4) gathered data about officers’ and suspects’ behaviors in connection with 7,512 adult

Director, National Institute of Justice Director, Bureau of Justice Statistics Robert J. Kaminski Program Manager, National Institute of Justice Points of view expressed by contributors to this report do not necessarily represent the official positions or policies of the U.S. Department of Justice.