Considerable scholarly attention has been devoted to examining factors that impact individual perceptions of improper police behavior. However, no one has unpacked specific explanations described by individuals to determine what people mean when they say that the police acted improperly towards them following an encounter. This dissertation uses the 2005 Police-Public Contact Survey (PPCS 2005) to examine the effects of the following factors on overall perceptions of improper police behavior, as well as by explanation type: prior contact, age, social class, gender, race/ethnicity, and intersections of gender and race/ethnicity. I test Turk (1969) and Blumer’s (1958) theories that individual positions in social stratification hierarchies influence perceptions of the police, along with Tyler’s (2001) conception of procedural justice, or perceived fairness of the encounter, as a key factor that determines individual perceptions of police behavior. Findings support the centrality of Turk (1969) and Blumer’s (1958) theory to perceptions of improper police behavior, especially with regard to race/ethnicity. Treatment throughout the encounter is also highlighted a key factor that influences individual perceptions of the police (Tyler 2001).