The purpose of the study was to investigate how and why injuries occur to police and citizens during use of force events. Specifically, the purpose of the national survey (Part 1) was to provide a snapshot of how less lethal force technologies, training, and policies are being used by state and local agencies. Agency-supplied use of force data were collected from law enforcement agencies in Richland County, South Carolina (Part 2), Miami-Dade County, Florida (Part 3), and Seattle, Washington (Part 4) to identify individual and situational predictors of injuries to officers and citizens during use of force events. Use of force records from multiple police agencies (Part 5) were collected and combined to investigate the relationship between situational and policy-related factors and the likelihood of injury to police and citizens. Lastly, longitudinal data were also collected to explore the effect of the adoption of the taser by the Orlando, Florida (Part 6) and Austin, Texas (Part 7) police departments on injury rates.
The research team conducted a national survey (Part 1) of a stratified random sample of United States law enforcement agencies regarding the deployment of, policies for, and training with less lethal technologies. As part of the process of developing and piloting the survey, three focus groups comprised of law enforcement practitioners were convened. The participants at the first focus group generated a list of issues pertaining to weapons deployment, policies, use-of-force continuums/models, training, reporting, and review. At the second focus group, the participants were asked to comment and provide feedback on the draft survey. The final focus group, comprised of law enforcement agency personnel, focused on a general discussion concerning who should fill out the survey within the target agencies and the participants' general impressions of the survey. Following the third focus group, the finalized surveys were mailed in July 2006 to 950 law enforcement agencies. A follow-up mailing was sent to nonrespondents three weeks later. Finally, a series of reminder letters was sent to the agencies that had not responded to any of the previous mailings. The first reminder was sent in September 2006; there were two subsequent reminders that were sent to nonrespondents approximately three and six weeks later. A total of 518 law enforcement agencies provided information on less lethal force generally and on their deployment and policies regarding conducted energy devices (CEDs) in particular.
Researchers also contacted, and obtained data from, law enforcement agencies in Richland County, South Carolina; Miami-Dade County, Florida; and Seattle, Washington; to identify individual and situational predictors of injuries to officers and citizens during use of force events. For the Richland County, South Carolina Data (Part 2), use of force reports completed by officers and maintained in paper files were coded and entered into a data file by trained graduate students. For both Part 2 and the Miami-Dade, Florida Data (Part 3), incidents were included in the dataset only if they involved a lone officer and a lone suspect. The purpose of this selection was to simplify the data for analysis. The Richland County, South Carolina Data (Part 2) include 441 use-of-force reports from January 2005 through July 2006, the Miami-Dade County, Florida Data (Part 3) consist of 762 use-of-force incidents that occurred between January 2002 and May 2006, and the Seattle, Washington Data (Part 4) consist of 676 use-of-force incidents that occurred between December 1, 2005, and October 7, 2006.
Further, the researchers obtained use of force survey data from several large departments representing different types of law enforcement agencies (municipal, county, sheriff's department) in different states. The research team combined use of force data from multiple agencies into a single dataset. The resulting Multiagency Use of Force Data (Part 5) includes 24,928 use-of-force incidents obtained from 12 law enforcement agencies from 1998 through 2007.
Lastly, longitudinal data were also collected from the Orlando, Florida, and Austin, Texas, police departments. The Orlando, Florida Longitudinal Data (Part 6) comprise 4,222 use-of-force incidents aggregated to 108 months -- a 9-year period from 1998 through 2006. The Austin, Texas Longitudinal Data (Part 7) include 6,596 force incidents aggregated over 60 months -- a 5-year period from 2002 through 2006.
For the national survey (Part 1), the research team used the services of Tailored Statistical Solutions, LLC (TSS) to draw a nationally representative sample of law enforcement agencies using the 2005 National Directory of Law Enforcement Agencies (NDLEA) database. The TSS stratified the agencies by type of law enforcement agency, region, and the size of the population served. Law enforcement agencies were categorized as State Police, Police Departments, or Sheriff Offices. United States Census categories were used to designate four regions: Northeast, Midwest, South, and West. The research team also developed seven categories of agencies denoting populations served: Under 10,000 people, 10,000 to 49,999 people, 50,000 to 99,999 people, 100,000 to 499,999 people, 500,000 to 749,999 people, 750,000 to 999,999 people, and 1,000,000 or more people. The objective was to select 1,000 agencies from the stratified target population to receive surveys. All 50 state police agencies were included, as were all 141 law enforcement agencies serving a population of 500,000 or more. All 6 Sheriff Offices in the Northeast region serving populations of less than 10,000 were also included with certainty. The remaining 803 law enforcement agencies were selected from the law enforcement agencies within the 35 other stratified groups, yielding a total of 1,000 law enforcement agencies. However, prior to survey distribution, the research team determined that 50 of those agencies were either duplicates of others in the sample, were no longer in existence, and/or were not of the appropriate agency type to participate in this survey. These were removed from the sample, yielding a final sample size of 950 law enforcement agencies, of which 518 responded to the survey.
The research team also utilized its contacts to obtain use of force data from the Richland County, South Carolina Sheriff's Department (Part 2), the Miami-Dade County, Florida Police Department (Part 3), and the Seattle, Washington Police Department (Part 4). Thus, these agencies represented a convenience sample.
To create the sample for the Multiagency Use of Force Data (Part 5), the researchers used the data generated from the Police Executive Research Forum (PERF) National Use of Force Survey to identify responding agencies that indicated that they captured injury information on officers and citizens and that they maintained use of force data in an electronic format. Only agencies that had at least 100 sworn officers and that reported issuing conducted energy devices (CEDs) to their officers were included in the selection process. After applying the selection criteria, 26 agencies were identified as possibly having data that met the requirements for the analysis.
The research team contacted the 26 agencies by telephone to further assess the compatibility of their data and to request their participation in the study. However, many of the 26 agencies did not actually have use of force and injury data available in an electronic format that could be accessed and converted into a data file for analysis. In other cases, the agencies' records management systems were not set up to easily retrieve the data. In addition, some agencies did not maintain the data that was needed in a database; rather, they captured and stored images of paper-based use of force forms (as PDFs or similar) that had to be downloaded and coded by hand. Still other agencies had major flaws in the way that they captured and stored information, which rendered their data
As the original list of 26 eligible agencies dwindled, the research team sought participation from other agencies with which it had contacts (and which were not survey respondents) and sought the assistance of PERF in identifying additional agencies whose data may have been suitable for analysis. This process resulted in the identification and participation of two additional agencies, but it also resulted in ruling out another handful of agencies which did not have suitable data. Finally, as the research team began constructing the
master dataset for the multiagency analysis, the team decided to include the data that it already had from the Miami-Dade County Police Department, the Richland County Sheriff's Department, and the Seattle Police Department. The final sample for Part 5 includes 12 law enforcement agencies. In addition to the Richaland County, Miami-Dade County, and the Seattle Police Departments, data were collected from the Austin, Texas Police Department, the Cincinnati, Ohio Police Department, the Harris County, Texas Sheriff's Department, the Los Angeles, California Police Department, the Los Angeles County, California Sheriff's Department, the Nashville, Tennessee Police Department, the Orlando, Florida Police Department, and the San Antonio, Texas Police Department.
Finally, after reviewing the data available for the multiagency analysis, the research team selected the law enforcement agencies in Orlando, Florida (Part 6) and Austin, Texas (Part 7) for its longitudinal data sample.
All law enforcement agencies in the United States in 2005 (Part 1); All use-of-force incidents in Richland County, South Carolina, from January 2005 through July 2006 (Part 2); All use-of-force incidents in Miami-Dade County, Florida, from January 2002 through May 2006 (Part 3); All use-of-force incidents in Seattle, Washington, from December 2005 through October 2006 (Part 4); All use-of-force incidents reported by 12 police agencies from January 1998 through December 2006 (Part 5); All use-of-force incidents in Orlando, Florida, from January 1998 through December 2006 (Part 6); All use-of-force incidents in Austin, Texas, from January 2002 through December 2006 (Part 7).
law enforcement agency (Part 1); use-of-force incident (Parts 2, 3, 4, and 5); use-of-force incidents aggregated by month (Parts 6 and 7)
National use of force surveys (Part 1); Administrative data (Parts 2, 3, 4, 5, 6, and 7).
administrative records data
The National Use of Force Survey (Part 1) contains a total of 292 variables including items about weapons deployment, force policies, training, force reporting/review, force incidents and outcomes, and conducted energy devices (CEDs). Specifically, weapons deployment variables include whether law enforcement agencies provide batons, CEDs, chemical agents, or other impact munitions (such as soft projectiles, bullets, or bean bags) to their patrolling officers.
Force policy variables in Part 1 include whether the law enforcement agencies use a force continuum/model in policy or training, the type of continuum/model used and whether it is in the process of being revised, whether officers are required to experience the effects of chemical sprays or the CEDs before they are authorized to carry them, and what type of force (soft empty-hand tactics, hard empty-hand tactics, chemical weapons, batons, CEDs in probe mode, or CEDs in drive stun mode) would be permitted under the agencies' use-of-force policy when officers are faced with different scenarios of suspect resistance (ranging from a suspect placing his hands behind his back and stating "I don't want to go to jail" to a suspect swinging at the officer's head with a closed fist).
Training variables in Part 1 include the total number of training hours received by the agency's most recent class of recruits, including the total hours of training spent on specific topics (firearms skills, self-defense, use of less-lethal weapons, and other scenarios), whether instruction was provided regarding a range of different topics (physical combat skills, arrest and control tactics, mediation skills/conflict management, use of CEDs, use of other less-lethal weapons, de-escalation and defusing techniques, use of deadly force, officer survival, and dealing with citizens with mental illness) and whether the training was mandatory for all sworn line-level police officers.
Force reporting/review variables in Part 1 include whether officers are required to submit documentation to report the use of several types of force (chemical agents, baton strikes with or without injury, CEDs in probe or drive stun mode, the pointing of CEDs, the use of other impact devices, bodily force resulting or not resulting in injury, neck restraint/unconsciousness-rendering holds, canine bites, vehicle ramming, firearms discharge at vehicles that hit or miss the vehicle, and pointing a weapon at a suspect), the individual who usually completes the mandated reports, the highest level (first-line supervisor, command level, or the chief/sheriff level) at which incidents would normally be reviewed for justification if no injury to the suspect occurs, and whether such reports are captured in an electronic database.
Force incidents and outcomes variables in Part 1 include whether the agency reports the amount of force used in terms of incidents, officer uses, or both, the number of incidents involving different types of force (civilians shot and killed, civilians wounded but not killed, civilians shot at but not hit, the use of a CED, chemical agents, batons, other impact devices, flashlights, empty hand tactics, the pointing of a weapon at an individual, the use of a neck restraint, canine bites, and vehicle ramming), the number of complaints resulting from use-of-force incidents that are generated by citizens or generated internally, the number of subjects that died as a result of officer-involved shootings, whether the department could produce annual totals for injuries to subjects or police officers when several definitions of 'injury' are used (injury, visible injury, complaint of injury, no injury complained of or observed, and death or serious bodily injury), and the number of officers injured during use-of-force incidents.
CED-related variables in Part 1 include the year that CEDs were first placed on the street, provided to patrol supervisors, provided to some or all patrol officers, or provided to one or more special units, the type of CED that is routinely deployed to various types of personnel, the minimum number of training hours necessary for officers to carry a CED, whether a written or practical examination is necessary before an officer can carry a CED, whether officers are required to undergo retraining following their initial CED training and the frequency of these retraining sessions, a ranking of different types of force (verbal control commands, chemical incapacitants, CEDs, control holds, strikes/punches, batons, chemical hybrids, kinetic weapons, incapacitation holds, and firearms), whether the agency's CED policy has changed since January of 2003, and whether the agency's use-of-force policy prohibits the use of CEDs under a series of special circumstances (including when the suspect is young, elderly, pregnant, and physically disabled), the number of activations of CEDs that are permitted by officers, and whether officer or subject injury information is included in the agency's CED report.
The Richland County, South Carolina Data (Part 2) contain 17 variables including whether the officer or suspect was injured, 8 measures of officer force (soft empty hand control, hard empty hand control, pepper spray, conducted energy device, baton, canine, gun aimed at suspect, and deadly force), 3 measures of suspect resistance (passive resistance, defensive resistance, and active aggression), the number of witnesses and officers present at each incident, and the number of suspects that resisted or assaulted officers for each incident.
The Miami-Dade County, Florida Data (Part 3) consist of 15 variables, including 4 measures of officer force (soft hands, hard hands, CEDs, and canine), the most serious resistance on the part of the suspect, whether the officer or suspect was injured, whether the suspect was impaired by drugs or alcohol, the officer's length of service in years, and several demographic variables pertaining to the suspect and officer (the suspect's age, race, and sex, and the officer's race).
The Seattle, Washington Data (Part 4) consist of 15 variables, including 3 measures of officer force (1 or more officers using bodily force, 1 or more officers using pepper spray, 1 or more officers using CEDs), whether the suspect or officer was injured, whether the suspect was impaired by drugs or alcohol, whether the suspect used, or threatened to use, physical force against the officer(s), and several demographic variables relating to the suspect and officer(s) (the average age of the officers, whether one or more officers involved were female, the proportion of non-white officers involved in the incident, and the suspect's race, sex, and age).
The Multiagency Use of Force Data (Part 5) include a total of 21 variables, including the year the incident took place, demographic variables relating to the suspect (age, sex, and race), the type of force used by the officer (pepper spray or CED), whether the suspect or officer was injured, and 5 measures of the department's policy regarding the use of CEDs and pepper spray (CED/pepper spray authorized for passive resistance, defensive resistance, flight, active resistance, and defensive or higher resistance).
Finally, the Orlando, Florida Longitudinal Data (Part 6) and the Austin, Texas Longitudinal Data (Part 7) are both comprised of seven variables documenting whether a taser was implemented, the number of suspects and officers injured in a month, the number of force incidents per month, and the number of CEDs uses per month.
Of the 950 agencies in the Part 1 sample, a total of 518 agencies completed the survey resulting in a 54.5 percent response rate. Response rates are not applicable for other parts in the data collection.