CHARACTERISTICS OF WASHINGTON, D.C. AND ITS CRIME PATTERNS ARE BRIEFLY PRESENTED, AND THE ORGANIZATION OF ITS LAW ENFORCEMENT OPERATIONS DESCRIBED. THE CRIMINAL INVESTIGATIONS DIVISION, THE FOCUS OF THE STUDY, IS EXAMINED RELATIVE TO ORGANIZATION AND OPERATIONS. CONCLUSIONS AND DESCRIPTIONS WERE DERIVED BY COMBINING DATA FROM INFORMAL INTERVIEWS, FIELD OBSERVATIONS, INTRADEPARTMENTAL MEMORANDUMS, TRAINING MATERIALS, GENERAL ORDERS, SUMMARIES OF STATISTICAL TRENDS, INVESTIGATIVE REPORTS, INHOUSE ANALYSES OF OPEN CASES, AND FILES ON CLOSED CASES. THE ANALYSIS OF THE INVESTIGATOR'S ROLE INCLUDES AN EXAMINATION OF THE SEQUENTIAL NATURE OF AN INVESTIGATION; THE SELECTION, TRAINING, AND DEPLOYMENT OF DETECTIVES; SOME IMAGES OF INVESTIGATIVE WORK HELD BY PATROL OFFICERS AND THE GENERAL PUBLIC AS WELL AS BY THE INVESTIGATORS THEMSELVES; AND SOME OBSERVATIONS ON INVESTIGATIVE TECHNIQUE. IN EXAMINING THE IMPACT OF THE DIVISION'S WORK ON THE PROSECUTION OF THEIR CASES, IT WAS FOUND THAT, COMPARED WITH OTHER CASES CONSIDERED FOR PROSECUTION, THE INVESTIGATIONS DIVISION HAD FEWER REJECTED IN THE SCREENING PROCESS AND A HIGHER CONVICTION RATE, APPARENTLY BECAUSE OF KNOWLEDGEABLE AND CAREFUL ATTENTION TO GATHERING EVIDENCE. TABLES ARE INCLUDED WITH INFORMATION ON THE ORGANIZATION, FUNCTION, AND WORKLOAD OF THE CRIMINAL INVESTIGATIONS DIVISION AND ON DEFENDANT AND CASE FLOW THROUGH THE D.C. SUPERIOR COURT. (RCB)