Can a stop and frisk turn into search and seizure?

Yes, a stop and frisk can lead to a search and seizure if the officer develops probable cause during the encounter. If an officer conducts a stop, and during a pat-down for weapons, they discover contraband or evidence of a crime, they may then have the legal basis to conduct a more thorough search. However, the initial stop must be based on reasonable suspicion, and any subsequent search must be justified under the Fourth Amendment to avoid being deemed unconstitutional.