Answer to Question 1
In Griffin v. Wisconsin, 483 U.S. 868 (1987), the Supreme Court held that a state law or agency rule permitting probation officers to search a probationer's home without a warrant and based on reasonable suspicion was constitutional.
All three of the Supreme Court decisions do not provide a great deal of guidance to probation officers on the streets. Griffin, for example, dealt with the constitutionality of one statute in one state. This means that probation officers are mostly forced to turn to state-level Supreme Court decisions for guidance.
Answer to Question 2
Reasonable suspicion was defined as a lesser degree of certainty than probable cause, but a greater degree of certainty than a hunch or unsupported belief. The term reasonable suspicion is found nowhere in the Constitution, but was created by the Supreme Court. The Court recognized that crime control could not be accomplished without a lower standard than probable cause. If probable cause was always required, police officers would not even be able to question people suspected of involvement in criminal activity without a high degree of justification.
The law governing stop-and-frisk attempts to achieve a balance between due process and crime control. On the one hand, controlling crime is in the public interest, and the police must be able to engage in certain activities to fulfill their duties. On the other hand, the public values their personal freedoms, and the Constitution is a highly prized guarantor of these freedoms. Many people, despite their desire to reduce crime, would object to aggressive search-and-seizure tactics by the police. Reasonable suspicion is something of a compromise between the conflicting goals of crime control and due process. It can be seen as achieving a balance between the needs of law enforcement and personal freedom.