Whether police may make a Terry stop based on reasonable suspicion that a person was involved in a completed felony, rather than an ongoing or imminent crime.
Holding
Yes. Police may briefly stop a person reasonably suspected, on specific and articulable facts, of involvement in a completed felony to investigate that suspicion.
Reasoning
The Fourth Amendment asks whether a seizure is reasonable, which requires balancing the intrusion on personal security against the governmental interests served. Terry's reasonable-suspicion standard is not confined by an inflexible rule to crimes that are presently occurring or about to occur. Earlier decisions had indicated that officers may act on reasonable suspicion that a person has been, is, or is about to be involved in criminal activity.
A stop to investigate a completed crime may lack some of the urgency associated with preventing an imminent offense. But it advances a substantial governmental interest in solving crimes and promptly bringing offenders to justice. Requiring officers to wait for probable cause could impede an investigation and allow a suspect to flee before police can identify or question the person.
The Court limited its holding to completed felonies. When a person is reasonably suspected of involvement in a felony, especially one threatening public safety, the public interest generally outweighs the intrusion of a brief detention no more extensive than a permissible Terry stop. The Court did not decide whether reasonable suspicion would justify stops to investigate every completed offense, regardless of seriousness.