Groton — Police are investigating vandalism at Fort Griswold Battlefield State Park in the City of Groton, and on Friday a crew power-washed much of the graffiti off.

Will Healey, spokesman for the state Department of Energy and Environmental Protection, said the department believes the graffiti happened over a very short period of time, likely last weekend.

"Among the various tags, the words 'Shoot to Kill' and 'Shooter' were spray-painted on the walls," he said.

Healey added that the department is "very disappointed with this kind of vandalism" and was getting the graffiti cleaned up as soon as possible. Seasonal part-time workers were able to remove a good portion of the graffiti from the outer walls of the fort's powder magazine Friday and will return Monday to continue until all of it is removed.

State Environmental Conservation Police and the Groton City Police Department are investigating.

City police Chief Michael Spellman said community members discovered the graffiti and reported it to the police department and there also were posts on Facebook with photos of the graffiti.

The fort was the site of the Revolutionary War Battle of Groton Heights between British forces led by Gen. Benedict Arnold — a Norwich native who had fought for the American side before turning coat — and American rebels on Sept. 6, 1781, during the burning of New London. Though the rebels at the fort surrendered after a brief fight, British soldiers reportedly continued killing them, and the engagement became a rallying cry for the Americans.

While DEEP is handling the primary investigation, since it is state property, city police are assisting due to the significance of the site to city residents.

"The Battle of Fort Griswold and the grounds up there are sacred ground to a lot of people that live in Groton City," Spellman said. "We still have descendants of people that fought in that battle that live in this community."

Spellman asked anyone with information about it to call city police at (860) 445-2451. Healey said people also can call a DEEP dispatch line at (860) 424-3333.

k.drelich@theday.com