TRENTON -- The annual report from the federal Bureau of Alcohol, Tobacco, Firearms and Explosives is a by-the-numbers account of New Jersey's struggle to stem the flow of illegal guns from out of state.

Every year, the ATF slices up state data on "crime guns" -- firearms seized by police and traced to determine their origin -- providing a top 10 list for the cities with the most seized weapons.

Typically, New Jersey's list is topped by its cities, which grapple with violent crime and illegal guns, but 2015 saw a new entrant:

Ringwood, New Jersey. Population 12,228.

The wooded cluster of lake communities in the Ramapo Mountains in northeastern Passaic County came in at number six on the ATF's list of cities with the most recovered weapons. It landed just below Camden, edging out East Orange, Atlantic City and 557 other New Jersey municipalities in terms of the number of crime guns.

The borough had 93 firearms seized and traced in 2015, the data show, but state and federal authorities say Ringwood isn't an overnight hot spot of gun crime.

One man's gun collection shot the tiny town near the top of the list.

On July 17, borough police arrived at the Skyline Drive home of Mariusz Cebula to seize his firearms as part of a temporary restraining order. What they found was later described as a "bunker" containing a cache of new and antique weapons and more than 40,000 rounds of ammunition.

"It's safe to say that the overwhelming majority of guns seized were from that one incident," Ringwood Police Lt. Peter McGinty told NJ Advance Media. He said at least 80 firearms from the town's 2015 tally came from the man's home.

The cache included dozens of World War II-era machine guns, a Mk19 grenade launcher, high capacity magazines and other items prohibited in New Jersey.

"It's a hunting community, so people do have guns here," McGinty said of his town, adding that in the past, police have seized weapons from hunters and collectors in domestic violence investigations, where state law requires police take custody of a defendant's guns until the case is resolved.

But nothing like that bunker. Including the weapons, de-activated ordnance, a silencer and other devices, the lieutenant said they catalogued more than 300 items.

"It took us a while to go through it all," he said.

Cebula pleaded guilty last month to a single count of possession of a machine gun in U.S. district court in Newark. Through a plea deal with prosecutors, he forfeited 27 of the weapons to federal authorities, court records show.

His attorney, Miles Feinstein, said that while Cebula took responsibility for possessing illegal weapons, "he did not use these weapons for unlawful purposes" and "there was no indication they had anything to do with crime or terrorism."

"He was basically a collector," Feinstein said.

Spokesmen for the State Police and ATF said Ringwood's inclusion on the list was a one-time anomaly.

Walter Kudron, a public information officer with the ATF's Newark field office, said federal law prohibits the bureau from releasing town-level data beyond what it publishes in its annual report.

The ATF report is an imperfect account of the guns seized in New Jersey. State attorney general guidelines call for every gun involved in a criminal investigation to undergo tracing, but not every department may fully comply.

The report's authors write in a disclaimer that "not all firearms used in crime are traced and not all firearms traced are used in crime," and a New York Times analysis of the data last year noted that the numbers are considered a conservative estimate of the size and scope of gun trafficking in the U.S.

Still, the report offers the best available window into the hidden flow of firearms, which in New Jersey come primarily from other states.

New Jersey has the highest percentage of crime guns sourced from out of state, at 78 percent.

In 2015, investigators identified the source state in 2,281 cases involving guns recovered in New Jersey. Of those traces, 500 came from within the state, and 1,781 came from states known for their more lax gun laws, including Pennsylvania and Georgia.

S.P. Sullivan may be reached at ssullivan@njadvancemedia.com. Follow him on Twitter. Find NJ.com on Facebook.