Federal crime in the United States

In the United States, a federal crime or federal offense is an act that is made illegal by U.S. federal legislation enacted by both the United States Senate and United States House of Representatives and signed into law by the president. Prosecution happens at both the federal and the state levels (based on the Dual sovereignty doctrine) and so a "federal crime" is one that is prosecuted under federal criminal law and not under state criminal law under which most of the crimes committed in the United States are prosecuted.

Source: Wikipedia — Federal crime in the United States (CC BY-SA 4.0)