Challenging the 'invariance' thesis: procedural justice policing and the moderating influence of trust on citizens' obligation to obey police

This paper examines the effects of a procedural justice policing intervention on citizens' feelings of obligation to obey police. It examines whether the efficacy of procedural justice on citizens' obligation to obey police may be contingent on citizens' level of trust in police during a police-citizen encounter. This research draws on survey data from the Queensland Community Engagement Trial (QCET). QCET was a randomized controlled field trial implemented by the Queensland Police Service. The trial exposed citizens to either a procedural justice experience (experimental condition) or standard police practice (control condition) during a random roadside stop. Survey responses were received from 1107 drivers in the experimental condition and 1655 drivers in the control condition. Compared to the control condition, the procedural justice condition yielded higher levels of trust in the police officer conducting the roadside stop. No differences in obligation to obey police were observed between the two conditions. Importantly, citizens' level of trust in the officer moderated the effect of the intervention on obligation to obey police. Specifically, the procedural justice condition had a negative effect on obligation to obey for those reporting low trust in police. For those high in trust, the procedural justice intervention had a slight but insignificant positive effect on obligation to obey. The findings suggest that procedural justice effects can vary between individuals; specifically, the findings reveal that procedural justice interventions can sometimes be counter-productive, depending on the level of trust a citizen exhibits toward police during an encounter. Police agencies should therefore be aware of potential counter-productive effects when implementing procedural justice in the field.