Criminal justice systems in the United States—in both state and federal courts—traditionally allowed judges to consider all of the facts and circumstances of a case to determine a convicted defendant’s appropriate sentence. But the United States Congress and many state legislatures have passed laws that force judges to give fixed jail or prison terms (mandatory minimum sentences) to persons convicted of certain crimes—often drug offenses, but also certain gun, pornography, and economic crimes.

For example, the Federal Sentencing Guidelines are non-binding rules that provide a uniform sentencing policy for defendants convicted of crimes in the United States federal court system. The Federal Sentencing Guidelines are not mandatory, but judges must consider them when determining a criminal defendant’s sentence—and when a judge exercises discretion and departs from the Guidelines, the judge must explain what factors warranted the increased or decreased sentence—known as an upward departure or a downward departure.

In Illinois, as in other states, the criminal justice system has experienced a shift from traditional discretionary sentencing to a more structured approach due to the implementation of mandatory minimum sentences for certain offenses. These mandatory minimums are predetermined periods of incarceration that a judge must impose for specific crimes, particularly drug offenses, as well as some gun, pornography, and economic crimes. This limits a judge's ability to consider the individual circumstances of a case when determining a sentence. However, judges in Illinois still retain some discretion for crimes not subject to mandatory minimums. At the federal level, the Federal Sentencing Guidelines provide a framework for sentencing in federal courts. While these guidelines are advisory rather than mandatory, federal judges are required to consider them and must articulate their reasons for deviating from the suggested sentencing range, whether imposing an upward or downward departure from the guidelines. It's important to note that while the guidelines are not binding, appellate courts may review sentences that significantly deviate from them.