BOSTON -- A Team 5 Investigates report last year on illegal gun trafficking into Massachusetts has led to an arrest by federal authorities.

NewsCenter 5's Sean Kelly reported that informants, including licensed gun dealers in addition to some criminals who watched Team 5's story, identified to police and ATF agents a man featured in our investigation. Agents said they've locked up a man who made money selling guns to felons.

Retired postal worker Michael Moccio's handcuffed wrists helped shield his face the day of his arrest. But when Team 5 Investigates went undercover at a Vermont gun show last year, he attempted to sell us, from Massachusetts, a handgun illegally.

"I'm not really supposed to sell handguns," he said.

"I was just hoping I'd be able to find somebody up here and let money do the talking you know," an undercover photographer said.

"Well, you know the Italian saying, 'Make me an offer I can't refuse.' You know what I mean? Then we can do something illegal," Moccio said.

"I'm willing to do $2,500 cash," the undercover photographer said.

Moccio said, "$2,500 cash -- that's tempting. I was figuring around the same thing. You got that kind of money?"

Team 5 did not buy the gun and no laws were broken. But now Moccio is under arrest. Team 5 Investigates was there when he was pulled from his home by federal and state authorities along with his .50 caliber assault rifles and 40 other guns.

Moccio did little to conceal that he was selling guns. In fact, he posted fliers on trees when he had a sale. He even advertised in the local paper. Sources tell Team 5 that hundreds of people have been to his house to buy guns.

Agents said one of the guns he sold was recovered at a murder scene.

Investigators said bullets shot from some of the guns could penetrate two school buses parked together 250 yards away.

Moccio has a permit for many of the guns but no state or federal license to sell them.

ATF agents said Moccio's $40,000 personal arsenal was up for sale to anyone for the right price.

"He was money driven. The more money he'd make, the more money he wanted to do it," said Chris Keniston, of the New York State Police.

The 61-year-old from Plattsburgh, N.Y., is charged as an unlicensed firearms dealer and with knowingly selling to convicted felons.

Team 5 met him in Vermont, one of 32 states where unlicensed dealers are allowed to sell privately under certain circumstances at gun shows to people without a background check.

Criminals in Massachusetts are known to go there, as well as New Hampshire and Maine, because it's easier to buy firearms.

Critics call this the gun show loophole.

"This loophole could be closed tomorrow if Congress and the president said all gun sales have to undergo a background check regardless of whether you're a private or a licensed dealer, and I think the number of guns sold to criminals would be dramatically reduced," said John Rosenthal, of Stop Handgun Violence.