There are about 800,000 police officers in the United States. Police officers protect the lives and property of citizens. They maintain order, catch lawbreakers, and work to prevent crimes. Also called “peace offers,” police officers have different responsibilities depending upon the size and structure of the communities in which they serve. Police officers may patrol the streets on foot or in squad cars, control traffic, or work as detectives investigating crimes. At the police station, officers may be assigned to work in the crime laboratory or the records department. All officers file reports of incidents, and many testify at trials and hearings.