The fall 1983 prison and inmate population forecast for Washington State is a transition forecast between projections based on assumptions underlying the operation of the current criminal justice system and assumptions of the system as it is expected to operate under the Sentencing Reform Act, which will be fully applied for 1987 and beyond. Because it is a transition forecast that reflects system changes, comparative information between the current system forecast and the forecast under the Sentencing Reform Act is provided. The forecast estimates the total inmate population from which two subsets of that population are derived: prison and inmate work release populations. Before discussing the findings and assumptions of the forecast, a brief summary of Washington's criminal justice environment and a historical overview are provided. The historical overview presents a perspective of the changes in the inmate population, with the major contributors to inmate population identified and discussed, including crime rates, target population, and the judicial decision to imprison. Following a presentation of the forecast findings for prison and inmate capacity forecasts, inmate admission and release forecasts, and monthly prison and inmate population forecast, assumptions and forecast changes are discussed. The forecast factors considered are crime, arrest, and felony filing rates; conviction rates; judicial decision to imprison; length of stay/releases; and recidivism rates. Appendixes contain the rationale for the projected conviction rates and judicial-decision-to-imprison percentages as well as historical and projected conviction rates and judicial-decision-to-imprison percentages. Tabular and graphic data are provided.