The Hopkinton Police Department issued a shelter-in-place order early Monday afternoon for the shopping plaza at 77 West Main Street, according to the deputy chief. It was lifted in less than an hour after the suspect told HPD he had been wearing a gas mask “for physical training purposes.”

HPD Deputy Chief Scott van Raalten explained in an email to the Independent on Tuesday that the department responded to “a report of a suspicious male wearing a black trench coat and gas mask in the area of 77 West Main Street.”

“The caller reported that the individual might be carrying a firearm, prompting an immediate and coordinated police response,” he stated.

The call was received at 11:58 a.m., according to the police log. Seven officers, including van Raalten and Chief Joseph Bennett, arrived at the scene one minute later, van Raalten shared. The plaza includes Crust & Co., Hopkinton Wine & Spirits, a nail salon and a pediatric practice.

The officers searched the exterior and interior of multiple businesses. They “advised occupants to shelter in place as a precaution,” van Raalten explained.

Additional command staff and officers from the Milford Police Department assisted in the investigation, he added. No individual matching the description was located in or around the plaza during the initial search.

“With the assistance of an on-site property manager, officers reviewed surveillance footage and identified a person believed to be a local resident, known to the department from prior disturbances,” the deputy chief continued. “The video showed the individual walking in the direction of his residence and did not show any firearm or other weapon in his possession.”

At the suspect’s home, officers observed a gas mask, according to van Raalten.

“The individual subsequently called the police station to apologize for the alarm caused,” he continued. “He stated that he had been wearing the gas mask for physical training purposes and that he did not have any type of weapon.”

The shelter-in-place advisory for businesses at 77 West Main Street was lifted at approximately 12:35 p.m. The incident was determined to involve no crime and no ongoing threat to the public.

Added van Raalten: “The Hopkinton Police Department appreciates the community’s vigilance and cooperation and encourages residents and businesses to continue reporting suspicious activity out of an abundance of caution.”