A randomized controlled study conducted with 1,854 police officers found a positive impact of the training on changing officers’ perceptions and approach in terms of police behavior “in the field”. The experiment identified significant, substantial, and positive effects of such training on all measures of the procedural justice model (voice, neutrality, respect, and trustworthiness) [1].
More specifically, the authors found that the training statistically significantly increased police officers’ perceptions of procedural justice principles (4.8% above the control group average). Moreover, it was found that this change in perception also translated into changes in behavior (the appropriateness index of the actions, attitudes, and interactions of the treated police officers was, on average, 4.1% higher than the index of the control group police officers). Finally, it was also found that the training of managers in procedural justice increased the effectiveness of the training of the officers under their responsibility and that the training also had positive effects on increasing the degree of identification of the officers with their institution and their profession.
In total, a randomly selected treatment group of 966 police officers, including their managers, participated in the training program, while the remaining 888 were included in the control group (i.e., did not participate in the training).