State police (United States)

In the United States, the state police is a police body unique to each U.S. state, having statewide authority to conduct law enforcement activities and criminal investigations. In general, state police officers or highway patrol officers, known as state troopers, perform functions that do not fall within the jurisdiction of a county’s sheriff (Vermont being a notable exception), such as enforcing traffic laws on state highways and interstates, overseeing security of state capitol complexes, protecting governors, training new officers for local police forces too small to operate an academy and providing technological and scientific services. They also support local police and help to coordinate multi-jurisdictional task force activity in serious or complicated cases in states that grant full police powers statewide.

A general trend has been to bring all of these agencies under a state-level 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." Forty-nine states have a State Police agency or its equivalent, with Hawaii being the only state with a Sheriff Division of the Hawaii Department of Public Safety with statewide jurisdiction.