Parking enforcement officers may be sworn police officers, depending on the city in which they work. In many major cities, including New York City and Los Angeles, parking enforcement is the responsibility of the police. In others, such as Chicago and Detroit, parking enforcement is mainly contracted to private third-party companies. Still other cities, such as Dallas and San Francisco, maintain parking enforcement services under municipal departments that are separate from the police department. Additionally, private properties, such as hospitals and colleges, typically use private security contractors to enforce parking restrictions.