Although methods of assessing and selecting police patrol officer candidates vary among the approximately 12,000 local and State police departments in the United States, many similarities exist between police departments. Police departments frequently use such approaches as written tests, background investigations, physical examinations, and interviews. Research has shown all police departments use background investigations and medical examinations. Generally, police departments emphasize the background investigation because such an investigation can ensure only the most qualified individuals are recruited and can also indicate an applicant's competence, motivation, and personal ethics. The medical examination can test for physical strength and agility, qualities necessary in the performance of police patrol officer duties. Some police departments use situational tests, for example, simulations of real-life scenarios, while other police departments use psychological testing, polygraphs, and assessment centers. Courts have encouraged the use of assessment centers as the most fair and job-related method of assessing police officer candidates. 18 endnotes, 2 tables, and 4 photographs