A partly enclosed coastal body of water in which river water is mixed with seawater is called an estuary. An estuary is thus defined by salinity rather than geography. Many coastal features designated by other names are in fact estuaries (for instance, Chesapeake Bay). Some of the oldest continuous civilizations have flourished in estuarine environments (for example, the Tigris and Euphrates rivers, the Nile delta, and the Ganges delta).
âFederal crimesâ refer specifically to offenses that violate U.S. federal laws. They are investigated by federal law enforcement and prosecuted by United States attorneys in federal courts with federal judges.
Mail fraud is a federal crime by nature, as using the postal service to advance a criminal attempt necessarily involves the federal government. There is a relatively clear statute in existence that defines mail fraud, and each of the two required elements is explained below.