Source: (2006) Criminal Justice and Behavior. 33(1):70-92.

For four vignettes that described minor criminal incidents, police officers indicated whether they would make an arrest and ranked the importance of four policing ideals in justifying their decision. These ideals were law enforcement, peace maintenance, procedural compliance, and assessing whether the protagonist accepted responsibility. Although an arrest was always warranted, the overall arrest ratewas 56%, and only10% of the officers always indicated an arrest. In justifying an arrest, law enforcement was ranked first on only 31% of occasions. Across arrests and nonarrests, the officers justified 66% of their actions using two combinations of ideals: lawprocedure and peace-procedure. Hence, the officers appeared to exercise their discretionary powers using one of two cognitive schemas to appraise each incident.