There are basically three types of law enforcement agencies, local, state, and

There are basically three types of law enforcement agencies, local, state, and federal. Local law enforcement agencies include police and sheriff departments. State agencies include the state or highway patrol. Federal agencies include the FBI and the U.S. Secret Service.
Police agencies in the United States function to enforce the statutes created by lawmaking bodies, and differing types and levels of legislative authority are reflected in the diversity of police forces in our country today. Consequently, American policing presents a complex picture that is structured along federal, state, and local lines.
Dozens of federal law enforcement agencies are distributed among 14 U.S. government departments and 28 non-departmental entities, and each federal agency empowered by Congress to enforce specific statutes has its own enforcement arm. The FBI may be the most famous law enforcement agency in the country and in the world. The mission of the FBI is to protect and defend the United States against terrorist and foreign intelligence threats, to uphold and enforce the criminal laws of the United States, and to provide leadership and criminal justice services to federal, state, municipal, and international agencies and partners.
State law enforcement agencies have numerous functions, including assisting local law enforcement departments in criminal investigations when asked to do so, operating centralized identification bureaus, maintaining a centralized criminal records repository, patrolling the state’s highways, and providing select training for municipal and county officers. State law enforcement agencies are usually organized after one of two models. In the first, a centralized model, the tasks of major criminal investigations are combined with the patrol of state
Local police agencies represent a third level of law enforcement activity in the United States. They encompass a wide variety of agencies, including municipal police departments, rural sheriff’s departments, and specialized groups like campus police and transit police.
Schmalleger, Frank. Criminal Justice Today (What’s New in Criminal Justice) (p. 163). Pearson Education. Kindle Edition.
Schmalleger, Frank. Criminal Justice Today (What’s New in Criminal Justice) (p. 163). Pearson Education. Kindle Edition.