The results of a randomized controlled trial of police body-worn video in Australia

Abstract

ObjectivesWe report the results of a randomized controlled trial of police body-worn video (BWV) cameras in an Australian context, with a focus on how cameras influence evidence gathering, court processes/outcomes, and police/public behavior.MethodsThe 6-month trial undertaken by the Western Australia Police Force involved a sample of officers (N = 498) acting as their own controls with camera use (“treatment”) randomly allocated across shifts. A range of parametric and non-parametric tests were conducted to explore the influence of BWV on interview efficiency, rate/timing of guilty pleas, conviction rates, sanction rates, police use-of-force, assaults against police, and citizen complaints against police.ResultsThe trial generated mixed results in support of this technology within this Australian context. BWV recordings did result in evidence-gathering benefits by producing cost/time efficiencies when taking field interviews. BWV footage had limited impact on court processes/outcomes, with indication that camera evidence encouraged earlier guilty pleas but no corresponding increase in the rate of guilty pleas or convictions. BWV did influence police operational decision-making, with increased sanction rates and use-of-force on treatment days. The extent to which officers engaged with the trial compounded these patterns. There was no evidence that BWV prevents problem behavior, with citizens’ complaints increasing on treatment days and no influence of BWV on rates of assaults against police.ConclusionsThese findings highlight the need for additional context-specific clarity about why police use BWV cameras. In particular, BWV users should clearly specify the causal mechanisms through which cameras will achieve administrative, evidentiary, operational, and/or problem-prevention goals.