These approaches include team policing, the use of civilians for some positions, and crime prevention programs requiring community involvement. In effect, police are increasingly being allowed to approach true professionalism. Although police have long considered themselves to be professionals, they have lacked two crucial elements: adequate training and freedom of discretion. They have been trained to make few decisions on their own and are trained to perform in accordance with prescribed standards intended to assure that they treat everyone alike. For decades the United States Supreme Court has issued decisions designed to limit police discretion. However, since the Terry decision in 1969, the Court has recognized that discretion is a central part of police methods. Courts have repeatedly ruled that police officers have both training and experience not common to others, based on which they should use increasingly wide discretion. Therefore, police supervisors should encourage the increased use of discretion, which is crucial to police effectiveness.