Eight experienced and eight inexperienced members of the An Garda Siochana police force in Ireland served as subjects. Four simulated patrol environments were created using slides taken on four local roads. Movement down the street was represented by slides giving forward vision, but at each point of forward vision there were collateral slides giving views to the side or rear at different angles. Using a random access slide projector and a map indicating slide position, subjects could explore the environment by choosing numbered positions on the map. A computer controlled the slide projector and recorded responses. Subjects were instructed to patrol the street as they normally would, using as many slides as they wanted to undertake their patrol. A number of systematic differences emerged between experienced and inexperienced officers. These differences primarily involved less use of suspicious activity cues by experienced officers. Study findings demonstrated that, in simulated patrol conditions, officers use environmental cues and that the extent of reference to such cues reflects both experience and instructions. 11 references, 1 table, 3 figures.