Most people are familiar with felony and misdemeanor criminal offenses, but it’s also possible to be charged with a federal crime. Federal charges are often among the most serious crimes, and they are prosecuted in the federal court system. Federal crimes are acts that have been made illegal by United States federal legislation, and although they may not be considered a criminal act under state law, they’re still enforceable by the federal government. In simple terms, federal criminal law ≠ state’s criminal law.
Most criminal acts involve a violation of state law, but if a criminal act occurs over state boundaries, or if the effects of the criminal activity could be felt nationwide, it is most likely addressed in the federal criminal code. Some examples would be kidnapping across state lines, organized crime, internet child pornography, threatening a federal public official, interstate drug trafficking, bank robbery, using U.S. postage service for any criminal purpose, and counterfeiting.
Prosecution guidelines are established by the United States Attorney in each federal judicial district and by laws that Congress has established.