Body-worn cameras (BWCs) have been implemented by the Las Vegas (Nevada) Metropolitan Police Department (LVMPD). BWCs are intended to increase transparency, improve police encounters, enhance evidence pertaining to an officer encounter, and provide opportunities for improvement through officer training. The LVMPD is a large police department, with approximately 2,600 sworn personnel (approximately 1,400 of whom are uniformed officers assigned to patrol division); the patrol division is divided geographically into eight “area commands” (Braga et al. 2018). The LVMPD began to use BWCs in 2011, because of a reform initiative in response to public criticism for the department’s use-of-force policies (Sousa 2016).
Per LVMPD policy (at the time of a study conducted in 2014), participating patrol officers are to activate their cameras as soon as possible during certain occurrences, including vehicle stops, person stops, calls for service involving citizen contact, detentions/arrests, search warrants, and pursuits. Officers are not required to obtain consent for recording, though policy states that they should inform the individuals being recorded.
Once the event has concluded, officers must deactivate their cameras following an announcement that they are doing so. If a recording needs to be retained, officers are required to label the recording using the following categories: 1) felony arrests, 2) misdemeanor arrests, 3) misdemeanor citations, 4) traffic citation with violation, 5) misdemeanor DUI arrests, 6) adverse citizen contact, 7) use of force–no arrest, 8) pursuit–no arrest, or 9) officer-involved shooting (OIS) deadly force. Depending on the category, recordings are held between 45 days (uncategorized) and 7 years (OIS deadly force/homicide) (Las Vegas Metropolitan Police Department N.d., p. 4–9).
As soon as possible following the event, or no later than the end of each shift, participating officers are to upload the recordings. To do so, they connect their BWCs to docking stations that are housed at four of eight command stations. This allows for seamless uploading of recordings and recharging of the device. Officers are permitted to view their own recordings in the following instances: 1) completing investigation and other official reports, 2) before a court appearance to refresh their memories, and 3) to provide a statement pursuant to an internal investigation. One caveat is that if an officer is involved in an OIS incident, the officer should upload the recording prior to viewing. Supervisors can view recordings for officers under their supervision in the following instances: 1) a use-of-force investigation, following the submission of a citizen complaint; 2) during an internal investigation; and 3) to assist in addressing a clearly documented performance issue (Las Vegas Metropolitan Police Department N.d., p. 9–10).
Due to union agreements (at the time of the study conducted in 2014), LVMPD officers could not be forced to wear BWCs; therefore, officers did so only voluntarily (Braga et al. 2018).
Deterrence and self-awareness theories are commonly used to suggest that placing BWCs on officers will improve police–citizen interactions by deterring undesirable behaviors and stimulating desirable behaviors. Deterrence theory suggests that crimes can be prevented when the costs of committing the crime are perceived by the offender to outweigh the benefits (Paternoster 2010). Self-awareness theory states that when focused on oneself, individuals evaluate and compare their current behavior to internal standards and values. This may then cause them to alter their behavior because they are aware that they are being recorded potentially for others to see (Braga et al. 2018). Thus, BWCs should deter bad behavior from both citizens and officers alike.
Officer Use of Force Incidents
Braga and colleagues (2018) found a statistically significant reduction in use-of-force reports for Las Vegas Metropolitan Police Department (LVMPD) officers who wore body-worn cameras (BWCs), relative to the non-BWC control group. The absolute difference between the BWC and non-BWC officers in the percentage of officers with at least one use of force report was a 12.5 percent reduction in favor of the BWC officers over the pre-intervention and intervention periods.
Citizen Complaint Reports
There was a statistically significant reduction in complaints from citizens for officers who wore the BWCs, compared with the non-BWC officers. The absolutely difference between the BWC and non-BWC officers in the percentage of officers with at least one complaint represented a 14.0 percent reduction in favor of the BWC officers over the pre-intervention and intervention periods.
There was a statistically significant increase in arrests for BWC officers, compared with non-BWC officers. Comparing monthly officer averages from the pre-intervention and intervention periods, BWC officers generated 5.2 percent more arrests compared with the non-BWC officers.
There was a statistically significant increase in citations for BWC officers, compared with non-BWC officers. Comparing monthly officer averages from the pre-intervention and intervention periods, BWC officers generated 6.8 percent more citations compared with the non-BWC officers.
Braga and colleagues (2018) conducted a randomized controlled trial to evaluate the impact of the use of body-worn cameras (BWCs) in the Las Vegas Metropolitan Police Department (LVMPD) on citizen complaints, use of force, and enforcement activity over a period of 18 months. The study involved 416 patrol officers. The treatment group included 218 voluntary patrol officers who used BWCs, compared with the control group, which consisted of 198 patrol officers who did not use BWCs. This study was conducted following an initial pilot of BWCs in 2011. Officers were identified and randomized to treatment and control groups beginning in February 2014 and continuing through September 2014.
Of the participating officers, 91.6 percent were male, and 72.4 percent were white, 13.2 percent were Hispanic, 8.9 percent were black, and 5.5 percent were Asian/other race or ethnicity. The average age was almost 37 years, and officers had on average more than 9 years on the job, all of which was consistent with the department as a whole. There were no statistically significant differences between the treatment and control groups on the baseline characteristics.
Due to union agreements at the time of the study in 2014, officers could not be forced to wear BWCs; therefore, participants in this study could do so only voluntarily. If participating, a patrol officer used the BWC in accordance with the LVMPD policy (Las Vegas Metropolitan Police Department N.d.). Following the intervention period, official complaint and use-of-force reports were gathered, and officers were identified with their unique ID numbers. Data was collected between March 1, 2011, and September 30, 2015 from the LVMPD Professional Standards Division.
Intention-to-treat (ITT) analysis was conducted on the outcome data, based on the initial random assignment to treatment rather than analysis of the treatment as actually received. The impact of BWCs on treatment officer activity relative to control officer activity was estimated through the difference-in-difference (DID) estimator, which estimates the difference in treatment officers’ post-intervention outcomes at time (t), compared with their pre-intervention outcomes and relative to the same difference for the control officers in the study. The issue of potential contamination arose pertaining to instances in which officers from the treatment group and control group responded to the same call. Though LVMPD officers patrol in one-officer units, the issue still arose in instances when back up was called, and the research design was ultimately not able to prevent contamination. The study did not conduct subgroup analyses.
These sources were used in the development of the program profile:
Braga, Anthony, James R. Coldren, William Sousa, Denise Rodriguez, and Omer Alper. 2017. The Benefits of Body-Worn Cameras: New Findings from a Randomized Controlled Trial at the Las Vegas Metropolitan Police Department
. Washington, D.C.: U.S. Department of Justice, Office of Justice Programs, National Institute of Justice.
Las Vegas Metropolitan Police Department. No date. “Body Worn Cameras.” Accessed January 17, 2019.http://ipicd.com/ceer/files/LVMPD%20BWC%20Policy.pdf
Paternoster, Raymond. 2010. “How Much Do We Really Know about Criminal Deterrence?” Journal of Criminal Law and Criminology
Sousa, William H., James R. Coldren, Jr., Denise Rodriguez, and Anthony A. Braga. 2016. “Research on Body-Worn Cameras: Meeting the Challenges of Police Operations, Program Implementation, and Randomized Controlled Trial Designs.” Police Quarterly