Final answer:
A "Terry stop" requires reasonable suspicion of criminal activity, a standard established by the Supreme Court, allowing police to prevent crime but raising concerns about racial profiling and overreach.
Step-by-step explanation:
To perform a "Terry stop," an officer must have reasonable suspicion that a person is involved in criminal activity. This concept stems from the landmark Supreme Court case Terry v. Ohio, which held that police may stop individuals based on reasonable suspicion of crime and conduct a frisk for weapons if there is reasonable suspicion that the person is armed and dangerous, without violating the Fourth Amendment.
This standard is less strict than the probable cause required for an arrest warrant. The ability to carry out such a stop provides law enforcement with a tool to address crime before it escalates, as supported by policies like Zero Tolerance Policing and Stop and Frisk, though these practices raise concerns about potential for racial profiling and abuse of police authority.
Another important case, New Jersey v. T. L. O., confirmed that the Fourth Amendment's ban on unreasonable searches applies to school officials, but they may use reasonable suspicion instead of probable cause. Moreover, in certain contexts such as car searches and border entries, police do not require a warrant to conduct a search.
Probable cause is necessary, though, when law enforcement seeks a warrant, ensuring they provide evidence indicating that a crime has been committed or evidence of a crime will be found.