A Terry stop in the United States allows the police to briefly detain a person based on reasonable suspicion of involvement in criminal activity.12 Reasonable suspicion is a lower standard than probable cause which is needed for arrest. When police stop and pat-down a pedestrian, this is commonly known as a stop and frisk. When police stop an automobile, this is known as a traffic stop. If the police stop a motor vehicle on minor infringements in order to investigate other suspected criminal activity, this is known as a pretextual stop.
In the United States at the federal level, the Supreme Court has decided many cases that define the intersection between policing and the Fourth Amendment protection against unreasonable searches and seizures. However, Congress has not defined a baseline for police behavior. There has been some state action at both the legislative and judicial levels, and also some cities have passed laws on these issues.34
Some law academics are concerned that jurisprudence permitting Terry stops does not account for possible of officers, and that this possibly results in decision-making. Communities that have high rates of may experience more intense and punitive policing and surveillance practices even during periods of time when general crime rates are decreasing.