First, it defines police by their ends rather than by the specific means that they use to achieve their goals. Second, the variety of situations in which police are asked to intervene is much greater than law enforcement and order maintenance. There is now a consensus among researchers, based on a definition first proposed by American sociologist Egon Bittner, that the common feature among all the different agencies engaged in policing is the legal competence to enforce coercive, nonnegotiable measures to resolve problematic situations. Such situations are characterized by two features: their potential for harm and the need to solve them urgently before they develop that potential. Hence, the actual use of coercion or the threat of using it allows police to put a quick, nonnegotiated, and conclusive end to problematic situations (e.g., keeping people away from the scene of a fire for their own protection and to allow firemen to do their job
