The case studies present the background and intent, key statutory provisions, and impact of the 1975 Firearm Law in Florida, the Uniform Determinate Sentencing Act in California, Public Law 148 in Indiana, Minnesota's Community Corrections Act, and House Bill 2013 in Oregon. Florida's mandatory minimum 3-year prison term for certain felony convictions involving firearms sought a greater deterrent effect through stiffer penalties and greater certainty of their imposition. Analysis of the law's impact found that the larger percentage of armed robbers serving 3 years or more after the law went into effect may result in a long-term gradual increase in the State's prison population, beginning in mid-1978. The results of California's determinate sentencing law generally violated the prelaw expectations of no change in admission volume and typical length of stay; in the 2 years since determinate sentencing went into effect in 1977, the volume of newly received felons is the largest in the history of the State, with short-term prison population increases as a result. The first 10 months' experience with the new Indiana criminal code, containing a number of mandatory imprisonment provisions, found no indication of increased prison admission volumes. Further experience is needed in Indiana to assess the law's impact on sentencing practices. Minnesota's Community Corrections Act of 1973, which promoted community-based alternatives to imprisonment, resulted in declining trends among participating counties in the probability of incarceration for convicted felons. Finally, the Oregon law, mandating the establishment of guidelines to be used by the parole board in determining the length of imprisonment time before parole release, resulted in increases in the proportion of the prison population paroled each year. Areas requiring future research are recommended, such as an analysis of the effects of changing statutes on policies and practices of specific agencies in relation to other factors which are believed to affect these agencies' contribution to the criminal justice system workload. Tabular data, graphs, and chapter notes are included, and appendixes present an overview of good time provisions and the reform laws of Indiana, Minnesota, and Oregon.