The federal government has the right to make laws to govern the citizens of the United States. When a person breaks one of these laws, it is considered a federal offense.
Sometimes federal laws and state laws regulate the same activities. If you commit an act that is illegal under both a federal law and a state law you can be convicted for the same act in both the state court and the federal court. It does not violate double jeopardy to be convicted in both courts.
Posted in: Federal Offenses