Although the term may encompass entities such as courts and prisons, it most frequently applies to those who directly engage in patrols or surveillance to dissuade and discover criminal activity, and those who investigate crimes and apprehend offenders.
Outside North America, such organizations are called police services.
In North America, some of these services are called police while some have other names (e.g. sheriff's office/department; investigative police services in the United States are often called bureaus (e.g. FBI, USMS, ICE, CBP, ATF, DEA, USSS etc.).
[2][3] History of law enforcement Criminal Investigation – applied science involving the study of facts, used to identify, locate and prove the guilt of a criminal.
[5] Modern-day criminal investigations commonly employ many scientific techniques known collectively as forensic science.