State police (United States)

In the United States, state police are law enforcement bodies unique to each U.S. state, possessing statewide authority to conduct law enforcement activities and criminal investigations. State police officers, commonly known as state troopers, typically perform functions that fall outside the jurisdiction of a county's sheriff, 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 coordinate multi-jurisdictional task force activity in serious or complicated cases.

Forty-nine U.S. states have a state police agency or its equivalent. Hawaii is the only state without a dedicated state police or highway patrol force, as its county police departments carry out highway patrol functions. Twenty-three states use the term "State Police" for their agency, while others use names such as "Highway Patrol," "State Highway Patrol," "State Patrol," or "State Troopers."

History

The Texas Rangers are the earliest form of state law enforcement in the United States, originally organized by Stephen F. Austin in 1823 for settlers in what was then the Mexican state of Coahuila y Tejas. They became an American law enforcement force following the annexation of Texas in 1845.

The Pennsylvania State Police (PSP), established in 1905, is widely considered the first modern state police department in the United States. It emerged in the aftermath of the anthracite mine strike of 1902. The New York State Police was formed on April 11, 1917, and the West Virginia State Police on June 19, 1919. Many early state police forces were created in response to labor unrest, with strikebreaking being a significant part of their original mandate. Over time, as the interstate highway system expanded and automobile use proliferated, their focus shifted toward traffic enforcement and general law enforcement.

The federal government in the 1920s was generally distrustful of southern states establishing state police, fearing the agencies would be used to oppress black citizens from voting and exercising civil rights. In response, many southern states initially established highway patrol agencies focused on motor vehicle and traffic regulation, which were later vested with general police powers.

Types of State Police Agencies

State police agencies in the U.S. generally fall into several categories:

• State Police: Full-service law enforcement agencies with general police powers and statewide jurisdiction. Examples include the Pennsylvania State Police, New York State Police, and Massachusetts State Police.
• Highway Patrol: Agencies primarily focused on enforcing traffic laws on state highways, though many also possess full police powers. Examples include the California Highway Patrol and Texas Highway Patrol.
• State Highway Patrol / State Patrol: Similar to highway patrol agencies, with names varying by state. Examples include the Ohio State Highway Patrol and Colorado State Patrol.
• State Troopers: Used by Alaska (Alaska State Troopers), which also operates the Alaska Highway Patrol as a bureau within the agency.

All but two state police entities use the term "trooper" to refer to their commissioned members; California and New Mexico are the exceptions, using "officer" instead.

Jurisdiction and Functions

State police agencies generally have jurisdiction throughout their entire state, unlike municipal police (whose jurisdiction is limited to a city or town) or county sheriffs (whose jurisdiction is limited to a county). Their primary functions typically include:

• Enforcing traffic laws on state highways and interstates
• Conducting criminal investigations
• Providing security for state government buildings and officials
• Operating state crime laboratories
• Training law enforcement officers
• Coordinating multi-jurisdictional task forces
• Providing specialized services such as aviation, marine patrol, and K-9 units

List of State Police Agencies by State

Territorial Police

Three of the five permanently inhabited U.S. territories have police departments with territory-wide authority: the Guam Police Department, the Puerto Rico Police Department, and the U.S. Virgin Islands Police Department. American Samoa and the Northern Mariana Islands also maintain territorial police forces.