FRIDLEY, Minn. - The frustrationinfirearms dealer Mike Briggs' voice is unmistakeable.

How else is a businessman supposed tofeel when he's been targeted by thieves three times in the past 15 months, losing tens of thousands of dollars in the process.

The latest break-in occurred around 9 p.m. Monday at the Trail's End Bass Pro Shopon the corner of Highway 65 and OsborneRoad in Fridley.Briggs says a boulder the size of a bowling ball was thrown througha plateglass window in front of the store, and then at least one personslipped through the ironsecurity bars inside.

Trail's End is still doing inventory but it is believed that between six and a dozen handguns were stolen Monday night. That's on top of dozens more handguns and assaultrifles takenduring two other break-ins, one in July of 2011 and another in July of 2012.

Briggs believes that the same people are responsible for all three thefts and says he suspects that the guns are being sold, perhaps by organized gangs. He is gathering money for a reward, and also wants to warn the community that additional firearms are now on the street. There is frustration in that Briggs has taken extra steps to make the business more secure and it still isn't enough.

Anyone who knows anything about the gun heists or those responsible is asked to call Fridley police.