Wikipedia
State police or '''provincial police '''are a type of sub-national territorial police force, found particularly in North America, South Asia, and Oceania. Some other countries have analogous police forces, such as the provincial police in some Canadian provinces. Particularly in the United States, the primary goals of most state police agencies are the safety of motorists on interstate highways, and the enforcement of traffic laws on those interstate highways, but can also involve statewide law enforcement and criminal investigation.
State Police (In Finnish: Valtiollinen poliisi (Valpo; literally "state police" or "governmental police") was the predecessor of the Finnish Security Intelligence Service.
In the United States, state police are a police body unique to each U.S. state, having statewide authority to conduct law enforcement activities and criminal investigations. In general, they perform functions outside the jurisdiction of the county sheriff (Vermont being a notable exception), such as enforcing traffic laws on state highways and interstate expressways, overseeing the security of the state capitol complex, protecting the governor, training new officers for local police forces too small to operate an academy and providing technological and scientific services. They support local police and help to coordinate multi-jurisdictional task force activity in serious or complicated cases in those states that grant full police powers statewide.
A general trend has been to bring all of these agencies under a State Department of Public Safety. Additionally, they may serve under different state departments such as the Highway Patrol under the state Department of Transportation and the Marine patrol under the Department of Natural Resources. Twenty-three U.S. states use the term "State Police." There are 49 states with State Police with Hawaii being the only state in the Union with no state police so named.