Short answers, pulled from the story.
The first recorded police force in history relied on trained monkeys, baboons, and dogs to guard markets and apprehend criminals in ancient Egypt. This force existed during the Old Kingdom period and the fourth dynasty when a position known as the Judge Commandant of the Police oversaw these early enforcement efforts.
Robert Peel established the Metropolitan Police in London in 1829. The main goal of this force was to change the principal object from general law enforcement to the prevention of crime through a philosophy known as policing by consent.
Searches for missing people accounted for 14% of police time in the United Kingdom in 2012. This statistic reflects the workload of patrol personnel who work 24/7 shifts to respond to calls for service and maintain order at public events.
The landmark case Miranda v. Arizona in the United States led to the widespread use of Miranda warnings. These warnings create safeguards against self-incriminating statements made after a person has been taken into custody.
The United States has a highly decentralized and fragmented system with over 17,000 state and local law enforcement agencies. This system includes local police, county sheriff's offices, state police, and federal agencies like the FBI.