Update: False Alarm; Rifle Turned Out To Be Bicycle Pump

Update: 12:04 p.m. 

Boston and state police swarmed the Horticultural Society at 300 Mass Ave. for a report of a man wearing a mask and carrying rifle on his back, but it turned out to be a bicycle pump.

Police did, however, find a ski mask in his possession.

Officers deemed the man was "no viable threat", and he's been sent for a mental evaluation.

"The motto is see something, say something, and that's what happened," said Superintendent William Evans, chief of patrol for the Boston Police.

A caller reported seeing a man with wearing a mask, a backpack, and a rifle on his back, shortly before 11 a.m.

"We treated it like it was an active shooter incident, and someone might want to do harm to a large group of people," Evans said.

Boston and State Police converged on the area, closing traffic on Mass Ave. and Huntington Ave. and creating a secure perimeter around the building.

"We did a diligent search and located the suspect in question," Evans said. He was found to be unarmed. Evans said he was carrying some sort of object, but couldn't confirm what it was.

Meanwhile, employees inside the Horticultural Society followed protocol by locking their doors, and not letting any outsiders into the building. The scene was clear by noon.

"It was a good training exercise," Evans said.