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 Louisiana, as in all states, federal crimes are offenses that fall under the jurisdiction of the federal government, as outlined by the United States Constitution and federal statutes found in the United States Code (U.S.C.). These crimes are distinct from state crimes, which are prosecuted under Louisiana state law, and typically involve matters that cross state lines or affect federal interests. Examples of federal crimes include, but are not limited to, bank robbery due to the federal insurance of bank deposits by the FDIC, tax evasion, wire and mail fraud, immigration offenses, and counterfeiting money. Federal crimes are investigated by federal agencies such as the FBI, DEA, and ICE, and are prosecuted by United States Attorneys in federal courts. The authority of the federal government to legislate and prosecute these crimes comes from specific powers granted by the Constitution, such as the power to regulate currency, interstate commerce, and matters of national security.