The department tweeted just before 4:30 p.m. that the hours-long stalemate was over, and the suspect was in custody and on his way to a hospital for evaluation.
Massachusetts State Police said the man was wanted on a theft charge. Police did not release the man's name or how the stand-off ended.
Officials said earlier that the man barricaded himself inside a bathroom at a Public Storage unit around 11:30 a.m. on Washington Street. Massachusetts State Police SWAT team members were on the scene along with Quincy negotiators trying to end the stand-off without violence.
Authorities said there was never any threat to the public.
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