Body-Worn Cameras and Police Use of Force: Is There a ‘Civilizing Effect’?

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Aug. 9 will mark the seventh anniversary of Michael Brown’s death in Ferguson, Mo., as well as the opening of a new phase in the national movement for police reform. Police body-worn cameras (BWCs) became an immediate and central feature in that effort, with a growing number of police agencies making them available to rank-and-file officers.

Less than five months after Brown’s death, then-President Barack Obama pledged $75 million for the purchase of 50,000 BWCs. In their 2015 final report, the President’s Task Force on 21st Century Policing highlighted BWCs as a tool that could potentially improve community trust and enhance police accountability.

michael White

Michael White

Moreover, several research studies published in 2014-2015 reported large reductions in use of force and citizen complaints after BWC deployment.[1] Since then, thousands of police departments in the U.S. have adopted the technology to avoid becoming the next Ferguson.

Flash-forward to May 25, 2020. Officer Derek Chauvin of the Minneapolis Police Department knelt on George Floyd’s neck for nearly nine minutes, killing him. Floyd’s horrific death, along with the police killings of Breonna Taylor and others have reignited the national outrage over police use of force.

Many now question whether we have made any progress at all in policing since Michael Brown’s death. Why do we still have a police use-of-force problem?

Weren’t BWCs supposed to fix that problem?

In fact, Chauvin and the other Minneapolis officers who killed Floyd had BWCs, and that footage featured prominently in Chauvin’s recent conviction on 2nd and 3rd degree murder charges.

Over the last six years, the BWC story has gotten increasingly mixed as several studies report no impact at all on use-of-force or citizen complaints.[2] Why would one police department experience a large reduction in those key measures after deploying BWCs, while another department has no change at all?

One way to approach answers is to focus on a core element of the presumed impact of BWCs: Can cameras improve behavior through a “civilizing effect”?

BWCs Impact on Use-of-Force and Citizen Complaints

As of April 2021, 29 studies have examined the impact of BWCs on citizen complaints, and 22 of 29 report substantial or statistically significant reductions.[3] Some 24 studies have examined the impact of BWCs on police officer use of force, and 11 of the 24 have documented reductions.[4]

One explanation for variation in research findings is local context. Not all police departments are the same. Not all communities are the same. Not all BWC programs are the same.

We think the weight of the evidence is still quite positive, especially for citizen complaints, but reductions are by no means guaranteed.

quin patterson

Quin Patterson

Why would BWCs lead to fewer citizen complaints or less use of force by police? One popular explanation is that BWCs cause police officers and citizens to behave better through a “civilizing effect.” This explanation has strong theoretical support (e.g., deterrence and social awareness theory)[5], and it makes sense. People will behave better if they are being watched (or recorded).

Unfortunately, researchers have not been able to test the civilizing effect directly. Whose behavior changes? The officer? The citizen? Both? Neither?

For the time being, let’s set aside officers and focus on citizens. A BWC-generated civilizing effect on citizen behavior cannot occur unless a few things happen first. These pre-conditions are:

      • There is a BWC present and the citizen is aware of it.
      • The officer activates the BWC (or at least, the citizen thinks it is recording).
      • The citizen is escalated (angry, upset, potentially violent) or has the potential to escalate (BWC can also generate a civilizing effect by keeping an already-calm person calm).
      • The citizen is capable of rational thought about the consequences of being recorded (not intoxicated, mentally ill and in crisis, traumatized, etc.).

If any one of these pre-conditions is missing, there can be no civilizing effect.

If the citizen is not aware of the BWC, there is no civilizing effect. If the BWC is not turned on, or the citizen does not think the camera is turned on, there is no civilizing effect. And so forth. All four pre-conditions must be present.

Our Study

 These pre-conditions are measurable if you watch encounters between police and citizens, which is what we did. Our research team went on ride-alongs and observed 166 encounters between citizens and officers in the Tempe (AZ) Police Department. For each interaction, we captured the prevalence of the pre-conditions. When all four occurred, we looked for a civilizing effect.

The results tell a simple story (see Figure 1).

Two of the four pre-conditions occurred frequently. First, Tempe officers almost always activated the camera (95.2 percent). Given how many police departments have struggled with low BWC activation rates, this is an important finding for Tempe PD. Second, most of the citizens appeared to be thinking rationally (82.5 percent). We drew our conclusions about this pre-condition based on the available evidence at the scene (e.g., confiscated narcotics), what the officer said and did (e.g., officer smelled alcohol), what the citizen said and did (e.g., mentioned mental illness or intoxication), and our own observations.

This is by no means perfect, but we think we captured a reasonable picture of citizens’ state of mind during these police encounters.

The low rates of the other two pre-conditions short-circuited the potential for a civilizing effect on citizens. Only 18.1 percent of citizens were escalated in the first place. Most were calm throughout the entire encounter. As we said above, BWCs can generate a civilizing effect by keeping a calm person calm, but for BWCs to maintain civility there must be citizen awareness of the camera.

Figure 1 shows that few citizens were actually aware of the BWC (3.8 percent). We documented citizen awareness only when there was concrete evidence of one of the following: verbal notification by the officer, the citizen mentioned the camera, or visual cues from the citizen that indicated awareness (e.g., pointed at the camera). Our measure is admittedly conservative, and we discuss this below.

Bottom line: all four pre-conditions occurred in only two of the 166 encounters. In those two encounters, one citizen was highly respectful throughout the encounter, while the other citizen’s behavior became more hostile by the end of the encounter.

Figure 1          The Prevalence of Each Pre-Condition for a Civilizing Effect on Citizens


We found little opportunity for a BWC-generated civilizing effect on citizens during these 166 encounters. The primary explanation is citizens’ lack of awareness of being recorded.

We admit our measure of awareness has limitations. For example, even if the officer did not notify the citizen and the citizen showed no clear recognition of the BWC, it is possible a citizen could be aware of the camera (e.g., the citizen saw a news story about the Tempe PD BWC program).

While we cannot rule out this possibility, research studies have consistently shown low rates of citizen awareness of BWCs when they are recorded.[6] Fortunately, there was little need for a civilizing effect as citizens were respectful to the officers in the vast majority of encounters.

What does this mean for police departments that currently use BWCs or who are thinking about deploying them?

Many departments adopt BWCs in order to experience the reductions in use of force and citizen complaints documented in some research studies. The results in Tempe suggest if reductions in those outcomes occur, it won’t be driven by changes in citizen behavior.

The story in other cities may be different than Tempe. Some police departments require officers to notify citizens of the BWC, other do not. Research studies have shown that activation rates vary significantly, from as low as 1 percent to as high as 99 percent.[7] In some cities, the prevalence of mental illness, substance abuse, and trauma far exceed what we witnessed in Tempe.

In fact, these differences may explain why some departments experience reductions in use of force and complaints while others do not.

What About Officers?

 If there is little chance for a civilizing effect on citizens, what about officers?

Most of these same pre-conditions also apply to police officers. With awareness of the BWC as a given, the most important pre-condition for officers is activation. We believe there is great potential for a civilizing effect on officers if the right mechanisms are in place to address this pre-condition.

First, departments should have a clear policy on when activation is required, when it is discretionary, and when it is forbidden.[8] The policy should be especially clear that all formal encounters with citizens must be recorded.

The policy should also explain the consequences for failure to activate, and most importantly, the department leadership must follow through on these consequences (see below). Also, departments should explore emerging automatic activation technology, which takes the “turn it on” decision out of the officers’ hands.[9]

Departments should also stay up-to-date on other innovations in BWCs that facilitate activation and improve the quality of video and audio captured (e.g., buffering, enhanced video, wider lens).

Last, first-line supervisors should monitor activation compliance through regular, random review of officers’ footage. General performance can also be monitored during this review. This is above and beyond the events that should automatically be reviewed: any use of force, any encounter in which a citizen or officer is injured, any incident resulting in a complaint, and any critical incident (pursuit, officer-involved shooting, etc.).

Officers must believe they will be held accountable for their actions, and BWCs provide a vitally important window into what happens during encounters with citizens.

Final Thoughts

 We believe the vast majority of police officers in this country behave appropriately, regardless of whether a BWC is present or not. Most officers treat citizens with respect. Most officers listen and display empathy. Most officers try to resolve citizens’ problems. Most officers only use force when necessary.

But there are some who do not. Clearly, Derek Chauvin had little concern about the consequences of his actions even though his BWC was recording.

We expect that the impending investigation of the Minneapolis Police Department by the U.S. Department of Justice will offer insights into why Chauvin displayed such ambivalence.[10] In all likelihood, Chauvin didn’t care because of organizational failures in terms of training, supervision, and policy. In plain terms, Chauvin didn’t expect to have to answer for his actions.

With BWCs and the proper accountability mechanisms in place, we believe there is great potential for a civilizing effect on officer behavior. And officers like Chauvin will be held accountable for their egregious, unlawful actions.

For more detail about this study, see:

Patterson, Quin & White, Michael D. (2021). Is there a civilizing effect on citizens? Testing the pre-conditions for body worn camera-induced behavior change. Police Quarterly.

Michael D. White, Ph.D., is a professor at the School of Criminology and Criminal Justice at Arizona State University and Associate Director of ASU’s Center for Violence Prevention and Community Safety. Quin Patterson, M.S. is Quin Patterson is a project coordinator in the Center for Violence Prevention and Community Safety at Arizona State University.

 [1] Ariel, B., Farrar, W., & Sutherland, A. (2015). The effect of police body-worn cameras on use of force and citizens’ complaints against the police: A randomized controlled trial. Journal of Quantitative Criminology, 31(3), 509–535.; Mesa Police Department. (2013). On-officer body camera system: Program evaluation and recommendations.;  Jennings, W. G., Fridell, L. A., & Lynch, M. D. (2014). Cops and cameras: Officer perceptions of the use of body-worn cameras in law enforcement. Journal of Criminal Justice, 22, 549–556.

[2] Yokum, D., Ravishankar, A., & Coppock, A. (2017). Evaluating the effects of police body-worn cameras. Washington, DC: The Lab@ DC20.



[5] Akers, R. L. (1990). Rational choice, deterrence, and social learning theory in criminology: The path not taken. Journal of Law and Criminology, 81(3), 653–676.; Beccaria, C. (1963). On crimes and punishments (H. Paolucci, Trans.). Bobbs-Merrill. (Original work published 1764); Duval, S., & Wicklund, R. A. (1972). A theory of objective self awareness. Academic Press.

[6] White, M. D., Todak, N., & Gaub, J. E. (2018). Examining body-worn camera integration and acceptance among police officers, citizens, and external stakeholders. Criminology & Public Policy, 17, 649–677.; White, M. D., Todak, N., & Gaub, J. E. (2017a). Assessing citizen perceptions of bodyworn cameras after encounters with police. Policing: An International Journal of Police Strategies & Management, 40(4), 689–703.

[7] Lawrence, D. S., McClure, D., Malm, A., Lynch, M., & La Vigne, N. (2019). Activation of body-worn cameras: Variation by officer, over time, and by policing activity. Criminal Justice Review, 44(3), 339–355.; White, M. D., & Malm, A. (2020). Cops, cameras, and crisis: The potential and the perils of police body-worn cameras. NYU Press.

[8] White, M. D., Patterson, Q., & Malm, A. (2020). Key trends in body-worn camera policy and practice: A five-year policy analysis of US Department of Justice-Funded Law Enforcement Agencies. CNA Analysis & Solutions.


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One thought on “Body-Worn Cameras and Police Use of Force: Is There a ‘Civilizing Effect’?

  1. Patterson and White never use the phrase “police violence” in reporting the results of their research. They talk about police use of force. Why the headline? Police use of force sometimes includes physical restraint, sometimes less lethal weapons and very infrequently firearms. The majority of use of force cases by police are handcuffing and restraint in order to take the person into custody. It is disingenuous to label all of these activities as violence. Another headline in a recent article called car stops police violence. Not helpful in an ongoing discussion on further reducing police use of force.

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