The flow model developed for this project is based on processing of all criminal cases in 1983. The model, written in Turbo Pascal and available on floppy disc for use in IBM personal computers or compatibles, distinguishes among 36 types of crime. It describes the flow courses of cases through police, prosecutors, and courts. The model describes the numbers and proportions of cases that are dealt with in certain ways, the final output of fines and custodial sentences, and the various resources available to cope with the annual caseload. The model has been used to examine the impact of changes in national policies toward crime in such areas as shoplifting and drunken driving. The model also was designed to be highly accessible to nonspecialized users, including administrators, prosecutors, and police officers. A revised version of the model has been developed that is based on the assumption that various criminal justice agencies adopt their policies to the presumed followup actions of other agencies and that each agency tries to cope with excessive workloads by adapting policies to reduce the required work. 1 figure, 1 table, 2 footnotes.