A New Jersey prosecutor Wednesday dropped the felony gun charge against a retired schoolteacher who was arrested last year when authorities discovered an unloaded, 300-year-old flintlock pistol wrapped in his car's glove compartment.

"I'm very appreciative that they exercised their discretion here and did the right thing," Evan Nappen, the attorney representing Gordon Van Gilder, told The Daily Journal.

The Cumberland County prosecutor said the state will exercise "prosecutorial discretion" in the case, but warned others about the laws pertaining to firearm possession, even if the gun is an antique. Van Gilder had faced 10 years in prison and the loss of his state pension if convicted. Nappen praised the prosecutor's decision.

Van Gilder, 72, who collects historical items, acknowledged the unloaded gun was in his glove compartment and wrapped in cloth when he was pulled over for a traffic violation in Cumberland County in November 2014, according to Nappen.

He had recently bought the gun and was planning to add it to his collection of antiques, which includes other old firearms, the lawyer said.

"This is a Queen Anne flintlock, which is a very pretty gun," Nappen said. "The barrel looks like a cannon and it has a single shot – you have to actually untwist the barrel to load it – it’s pretty involved to even attempt to load it. But the craftsmanship is from the 1760s, and it’s just magnificent to think that every piece of it was handmade.”

The flintlock is in the county's custody and Van Gilder plans to retrieve the gun.

But New Jersey law does not exempt antique firearms, said Nappen, who recently defended a Pennsylvania single mother who was pulled over just across the New Jersey border with a registered gun she carried for protection. In that case, Nappen helped his client avoid a 3-year mandatory minimum sentence only after widespread publicity, including extensive coverage by Fox News, led the state Attorney General's Office to drop the case.