Criminal offenses under state and federal laws are generally categorized by the seriousness of the crime as felonies (more serious) or misdemeanors (less serious). Felonies are offenses that generally may result in prison sentences of more than one year, and misdemeanors carry sentences of one year or less. The United States Congress sets the penalties for all federal criminal offenses, and thus decides which criminal offenses are felonies and which are misdemeanors. And the state legislature in each state decides which criminal offenses are felonies and which are misdemeanors under state law.

In South Dakota, as in other states, criminal offenses are classified into felonies and misdemeanors based on their severity. Felonies are the more serious crimes, potentially leading to imprisonment for more than one year, and in some cases, may even result in life imprisonment or the death penalty for the most severe offenses. Misdemeanors in South Dakota are less serious offenses and are punishable by incarceration for up to one year, usually in a county jail rather than a state prison, and/or by fines. The South Dakota Legislature has the authority to define state crimes and their respective classifications and penalties. For federal offenses, the classification and penalties are established by the United States Congress. It is important to note that some crimes may be considered a felony under federal law but a misdemeanor under state law, or vice versa, depending on the specific statutes and the jurisdiction in which the offense is prosecuted.