Expectancy motivation theory (Vroom, 1964) reasons that employees will perform tasks if they are expected to do so, have the ability to do so, the opportunity to do so, and believe that their efforts will be rewarded. This theory has been applied successfully in explaining differences in individual officer behavior regarding arrest productivity, which is easily measured. In applying this theory to a task less susceptible to data collection and analysis, the theory was not well suited to explaining officer variation in work activities not easily verified. The results indicate that of the variables included in the current model, the number of minutes an officer spends each shift conducting security checks is best predicted by whether or not the officer is working a midnight shift, whether or not he/she perceives security checks as a priority of the supervisor, whether or not the officer spends part of the shift on foot patrol, and the number of times during the shift that the officer has contact with a supervisor. The findings also suggest that these predictors are generally weak and only explain a small proportion of the variation between officers regarding the amount of time spent on security checks. Data used in the analysis came from the 1977 Police Services Study (PSS), which involved the systematic observation of patrol officers and field supervisors from municipal police agencies in Rochester, NY; St. Louis, MO; and Tampa-St. Petersburg, FL. Sixty trained observers accompanied officers on patrol for more than 7,000 hours of observation. Researchers observed officers during their shifts and recorded data on the activities they observed the officers perform. 1 note, 2 tables and 19 references