Research was conducted to develop the Police Career Index (PCI) and the regional assessment center exercises to provide a total personnel evaluation system to help police departments screen applicants, evaluate on-the-job performance of officers eligible for promotion, and gauge a person's suitability for police work. The PCI is based on actual performance criteria developed through cooperation with police officials in nine cities throughout the country. It measures how well an individual might handle four different police jobs--patrol officer, patrol sergeant, investigator-detective, and mid-level commander. This easily administered, objectively scored written test screens out high-risk applicants. Those who register borderline scores are referred to a regional assessment center where a series of police job simulations elicit behavioral indicators of potential for success in various aspects of police work. Local departments may wish to consider the 2-fold system, tested with good results in several cities. About half of this report consists of description of the research to develop and validate the PCI and the assessment center exercises. Appendixes include job description booklets for precinct patrolman, investigative personnel, sergeants, and intermediate commanders (about 50 pages). The remainder is research data tables. (TA)