There are two knowledge perspectives in police organizations, the theoretical perspective and the street-level perspective. These perspectives mostly understand phenomenon in the organization in different ways. The distance between both perspectives is large and a negative circle in knowledge exchange between the two perspectives increases the polarization (or division). A theoretical view of knowledge represents the main influence on how information and knowledge will be organized in law enforcement, and the theoretical perspective will tend to dominate. Unfortunately, the street-level perspective is often ignored. However, it is important that the decisionmaker at a high level in the organization try to understand and influence the street-level perspective. Researchers have studied classifications and categorizations of knowledge. This paper describes and classifies different types of knowledge that are a part of police patrol officers’ practice. The paper discusses different forms of professional knowledge separately to enable categorization. In general, a large part of police officers’ professional knowledge is complex and difficult to describe and explain in words. Figure, references