Transit police are a specialized police agency or unit employed by a common carrier, which could be a transit district, railroad, bus line, other transport carrier, or the state. Their mandate is to prevent and investigate crimes committed against the carrier or by or against passengers or other customers of the carrier, or those committed on the carrier's property.
A transit police force may consist of officers employed directly by a transit system, such as the Amtrak Police, or it may exist as a specialized unit of a local police force, such as the Transit Police Services Bureau of the Orange County, California Sheriff's Department, which serves the Orange County Transportation Authority or South Coast British Columbia Transportation Authority Police Service which serves the transit system of southern British Columbia, Canada.
Where the term "transit police " is used for the police working for a railroad/ railway, it usually refers to a railroad providing urban mass transit (such as a city elevated system or subway) as opposed to long-distance rail carriage. Police who work either for a private non- passenger railroad or long-haul rail carrier are usually referred to as "railroad police " or " railway police ". In Britain, most of the rail system, including the London Underground, is policed by a national transport police agency, the British Transport Police. Some transit police forces have full policing powers, such as BART Police, SEPTA Transit Police, Metro Transit Police Department, Utah Transit Authority Police Department or MBTA Transit Police, while in other areas, they have limited powers and are classed as special police or special constables with limited powers.
Some of the crimes transit police and railroad police investigate include trespassing on the right -of-way of a railroad, assaults against passengers, tagging of graffiti on railroad rolling stock and buses or bus stops, pickpocketing, ticket fraud, robbery and theft of personal belongings, baggage or freight, and drug dealing at transit stations. They may also engage in random ticket checking hoping to catch and fine ticketless travelers. These controls are usually more frequent in transit systems using an honor-based fare collecting approach.
