Police in New Jersey say a man was building machine guns right under their noses.

The man, 38-year-old Russell Watt of Hamburg, is with unlawful possession of a firearm and ammunition, according to police. They say he was taken into custody Monday at a shop where he works as a machinist.

The gun bust happened right across the street from the Franklin Borough Police Department, a playground, a senior center and a football field. Police said they were executing a search warrant for another matter when they stumbled upon the weapons.

“They did seem operable,” Franklin Police Department Det. Nevin Mattesich said. “He did have some parts that we did seize that were parts to make some additional high-powered firearms.”

Officials say weapons seized were long guns, hand guns, semi-automatic weapons, fully automatic machine guns, high capacity magazines and hollow point bullets.

Police believe Watt was buying some of the parts for some of the weapons online and manufacturing them at his job site. They also believe he was working alone.

Detectives are still looking into whether the weapons were for personal use, resale, or both. They said Watt has no previous weapons convictions.

“We are glad that we were able to put a stop to it this close to home,” Mattesich said.

Nobody was at the shop when News 4 knocked on the door for comment. It wasn’t clear if Watt had an attorney who could comment on the allegations.