Police Officers' Decision Making and Discretion: Forming Suspicion and Making a Stop

• NCJ Number: 213004
• Author(s): Geoffrey P. Alpert; Roger G. Dunham; Meghan Stroshine; Katherine Bennett; John MacDonald
• Date Published: October 2004
• Length: 151 pages
• Grant Number(s): 2001-IJ-CX-0035
• Agencies: NIJ-Sponsored
• Publication Type: Report (Study/Research)

Annotation

Based on observations and debriefings of police officers in Savannah, GA, this study identified factors that caused officers to make stops of individuals and vehicles.

Abstract

Characteristics of the person stopped were not found to be a significant factor in why an officer decided to make the stop. Officers were equally likely to stop individuals who were male or female, Black or White, or of low or high socioeconomic status based on appearances. In most of the cases where stops were made, the behavior of the suspect was what concerned the officer. Appearances of individuals and vehicles only became important in stops when they matched descriptions of suspects for traffic violations or crimes that had been reported. In the majority of cases, the behavior was associated with driving a vehicle rather than being a pedestrian. Officer observation of a traffic violation, obvious efforts to avoid the officer, and acting nervous in the officer's presence were common behaviors that caused officers to stop individuals. Time and place were not significant in officers' decisions to make stops. Officers did not make stops impulsively based upon initial notice of an individual or vehicle. Stops were not usually made until after continued observation confirmed an initial suspicion that a stop might be required. During the summer and fall of 2002, field observers accompanied officers in each of the city's four precincts and on all three shifts. Observers went on 132 tours that involved 174 occasions when officers contemplated and/or made stops of vehicles and pedestrians. Observers were trained to watch for the interactions between the officer and suspect, to document what they saw, and to note the sequence of events. Structured questionnaires guided observers in debriefing officers about their decisions related to making stops. Extensive figures and tables, 5 references, and appended study forms