PurposeThe purpose of this paper is to demonstrate how suspicion that leads to a police stop is developed by police officers in Belgium, and the way in which police department culture influences the creation of suspicion.Design/methodology/approachThe data on which this article is based are the result of an ethnographic study within two local Belgian police forces. In total, the researcher has observed for a total amount of 750 h the day-to-day practices of police officers in different police services. Next to that, 37 in-depth interviews were taken from police officers employed in the same services that participated in the observations.FindingsWhile the creation of suspicion in a police officer's mind is a complex process that is influenced by various factors such as the individual characteristics of the police officer and the applicable legislation, the impact of police department culture is equally important and can be responsible for maintaining discriminatory and stereotypical mindsets.Originality/valueThe originality of this paper lies in the fact that it offers insight into the Belgian police stop practice, a topic about which not much is known on an international level. In addition, it also focuses on the role of departmental cultures in the actions of police officers.