Whether a known informant's unverified tip that a person has narcotics and a gun can provide reasonable suspicion for a forcible investigatory stop.
Holding
Yes. The tip bore sufficient indicia of reliability to justify a Terry stop, even though it may not have established probable cause for an arrest or warrant.
Reasoning
Terry v. Ohio permits an officer to make a brief forcible stop on less than probable cause when the facts known to the officer make that intermediate response reasonable. The Fourth Amendment does not require an officer either to make a full arrest without probable cause or to ignore a credible report of possible criminal activity and danger.
Reasonable suspicion need not rest solely on an officer's personal observations. Informant tips may vary in reliability, and some anonymous or unsubstantiated tips will justify no forcible police action. But a tip from a known person who personally approaches an officer and provides information that can be promptly checked at the scene has greater reliability than an anonymous telephone report.
Here, Connolly knew the informant personally and knew that the informant had given him information in the past. The informant appeared in person, identified a particular nearby suspect, and gave a specific, immediately verifiable description of the location of a weapon. Connecticut law also exposed a person who knowingly made a false crime report to criminal liability. Taken together, these circumstances supplied sufficient reliability for a stop, though not necessarily enough for a narcotics arrest or search warrant.