Report: increases in police use of force in the presence of body-worn cameras are driven by officer discretion: a protocol-based subgroup analysis of ten randomized experiments

Abstract

Objectives Our multisite randomized controlled trial reported that police body-worn cameras (BWCs) had, on average, no effect on recorded incidents of police use of force. In some sites, rates of use of force decreased and in others increased. We wanted to understand these counter-intuitive findings and report pre-specified subgroup analyses related to officers' discretion on activating the BWCs. Methods Using pre-established criteria for experimental protocol breakdown in terms of treatment integrity, ten experimental sites were subgrouped into Bhigh-compliance( no officer discretion applied to when and where BWCs should be used; n = 3), Bno-compliance^(treatment integrity failure in both treatment and control conditions; n = 4), and tests where officers applied discretion during treatment group but followed protocol in control conditions only (n = 4). Results When officers complied with the experimental protocol and did not use discretion, use of force rates were 37 % lower [SMD = (−.346); SE = .137; 95 % CI (−.614) -(−.077)]; when officers did not comply with treatment protocol (i.e., officers chose when to turn cameras on/off), use of force rates were 71 % higher [SMD = .392; SE = .130; 95 % CI (.136) -(.647)], compared to control conditions. When full discretion (i.e., overall breakdown of protocol) was applied to both treatment and control conditions, null effects were registered [SMD = .009; SE=.070; 95 % CI (−.127) -(.146)], compared to control conditions. Conclusions BWCs can reduce police use of force when then officers' discretion to turn cameras on or off is minimized-in terms of both case types as well as individual incidents. BWCs ought to be switched on and the recording announced to suspects at early stages of police-public interactions. Future BWCs tests should pay close attention to adherence to experimental protocols.

Evaluation of operation swordfish: a near-repeat target-hardening strategy

“…Future experiments might actively construct monitoring mechanisms in both test and control areas for this purpose. As noted above, this might involve the use of body-worn video (Ariel et al 2016), with a sampling regime of the video evidence used to test for experimental fidelity in real-time. An appropriate cycle of feedback regarding implementation (e.g.…”

Paradoxical effects of self-awareness of being observed: testing the effect of police body-worn cameras on assaults and aggression against officers

“…In deterrence theory terms, the perceived likelihood of apprehension is substantially elevated in treatment conditions than control conditions. While under both experimental arms the behavior may have been modified as a result of the spill-over, the extent of the behavioral modification under control conditions cannot be assumed to be the same as that which has taken place under treatment conditions -otherwise we would not observe significant differences between treatment and control conditions across multiple outcomes, using this research design (e.g., Ariel et al 2015;Ariel et al 2016a;Ariel et al 2016b). For these reasons, were mistaken when giving a medical analogy for this treatment contamination ("both groups are taking the pill").…”

“…This may be true for officers who once wore BWCs and no longer wear them (through the process of random assignment) or officers in the department who did not take part in the experiment (e.g., neighborhood police teams, special victim support units). Ariel et al (2016b) argued that BWCs affect entire police departments through a process they labeled Bcontagious accountability.^Everyone is affected by the BWCs, even when the cameras are not in use; thus, the subculture has become less aggressive and more compliant with procedures.…”

Examining Body‐Worn Camera Integration and Acceptance Among Police Officers, Citizens, and External Stakeholders

“…() found a statistically significant decline in citizen complaints in only two of the ten London police boroughs examined. Ariel and colleagues () reported mixed findings across ten studies, resulting in an overall null effect on use of force. They also found a troubling link between BWCs and increased rates of assaults on officers (Ariel et al., ).…”