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 Missouri, 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 require judges to impose predetermined sentences for specific crimes, particularly drug offenses, as well as some gun, pornography, and economic crimes, thereby limiting judicial discretion. However, it's important to note that Missouri state law may have its own set of sentencing guidelines and mandatory minimums that differ from federal law. At the federal level, the Federal Sentencing Guidelines provide a framework for sentencing in federal courts. While these guidelines are advisory rather than mandatory following the U.S. Supreme Court's decision in United States v. Booker (2005), federal judges must still consider them and provide reasons for any departure from the suggested sentencing range. In Missouri, when a judge decides to deviate from the guidelines or mandatory minimums, they must similarly provide an explanation for their decision, whether it results in a harsher (upward departure) or more lenient (downward departure) sentence than the one prescribed by the guidelines or statutory mandatory minimums.