There are several types of Law Enforcement agencies in the US, these are the main ones each having different levels of jurisdiction:
Federal Police report at the highest level and have full authority given to them by the U.S.C (United States Code). They have full jurisdiction for all federal law enforcement.
State Police may also be known as Highway patrol, their main purpose is to oversee traffic safety and compliance, they are responsible to assist with road traffic accidents and securing the scene and providing first aid if needed. Their job is to enforce laws and regulations to make roads safer.
County Police are generally only found in city counties and have countywide jurisdiction. In some counties you have County police as well as a sheriffs department.
A Sheriff is the top law enforcement of the county. The law enforcement agencies that have a Sheriff are known as Sheriff's department or Sheriff's county. There are over 3000 Sheriffs departments in the US, some very small rural areas with only two or three members. The largest Sheriff's department in the US is Los Angeles, with over 16,000 members with approximately 400 reserve deputies.
Municipal Police range from very small agencies to the largest being the New York City Police department with up to 40,000 members. Municipal police are controlled and paid by the local government, they often have fewer rights than the state police and have restrictions on what arms they are allowed to carry.
There is also a whole list of other, specialist police departments in the US, here are just a few:
- Airport Police
- Park Police
- Border Patrol
- Postal Inspection Service
