Federal crimes are criminal offenses based on legislation (laws or statutes) enacted by the United States Congress and published in the United States Code (U.S.C.). Most crimes (murder, rape, assault, burglary, etc.) are prosecuted under state law (statutes) and are known as state law crimes. In contrast, crimes prosecuted under federal law are known as federal crimes.

Federal crimes generally involve a subject over which the United States Constitution gives the federal government—and more specifically, the U.S. Congress—the power or authority to legislate or make laws. This power or authority is also known as jurisdiction.

For example, the federal government (and not the states ) has the exclusive authority to print money and regulate its value. And because bank deposits are guaranteed (insured) by the federal government (FDIC) up to $250,000 per depositor, per FDIC-insured bank, and per ownership category, bank robbery is a federal crime (18 U.S.C. §2113). Examples of other federal crimes include tax evasion, wire fraud, mail fraud, immigration offenses, voting or electoral fraud, counterfeiting money, espionage (spying), and damaging or destroying mailboxes.

In South Dakota, as in all states, federal crimes are offenses that are prosecuted under the authority of laws passed by the United States Congress, as opposed to state statutes. These crimes are codified in the United States Code (U.S.C.) and typically involve matters under federal jurisdiction, which is granted by the U.S. Constitution. Federal crimes often pertain to issues that cross state lines or affect the nation as a whole, such as counterfeiting, bank robbery due to federal insurance of bank deposits, tax evasion, and immigration offenses. For instance, bank robbery is a federal crime under 18 U.S.C. §2113 because banks are federally insured by the FDIC. While state law crimes like murder and assault are generally prosecuted by state authorities, federal law enforcement agencies such as the FBI, DEA, and ATF, along with federal prosecutors, handle the investigation and prosecution of federal offenses. Attorneys representing the federal government in such cases are typically known as U.S. Attorneys.