They protect the life and property of others. In most jurisdictions, whether on or off duty, police officers are expected to exercise their authority whenever necessary. Police officers in small communities and rural areas have many duties. In the course of a day's work, they may direct traffic at the scene of a fire, investigate a burglary, or give first aid to an accident victim. Officers in a large police department are usually assigned to a specific type of duty.
Most officers are detailed either to patrol or to traffic duty.
Those on patrol duty may be assigned to a certain area with which they must become familiar and be aware of any unusual happenings. Officers who are assigned to traffic duty may direct traffic, ticket or arrest persons who do not obey traffic laws, and watch out for stolen cars and other suspicious situations. A small number of police officers are assigned to special work such as accident prevention. Some investigate robberies, homicides, and other crimes. Others are experts in chemical and microscopic analysis, firearms identification, and handwriting and fingerprint identification.