Charles Preston, and at right, his son Justin Preston, were arrested in Nashua, N.H., Sept. 14, 2013. Nashua Police Dept.

An alleged father and son robbery team are in jail today after their attempted heist of a bingo hall was thwarted when they were attacked by the bingo players, police said.

Charles Preston, 46, and his son Justin Preston, 20, are charged with trying rob the Eagle's Wings Function Center in Nashua, N.H., Saturday.

The elder Preston walked up to two bingo hall employees counting money, pulled out a gun, pulled the trigger twice on the apparently unloaded gun, and demanded the employees hand over the cash, police said. When the employees complied and Preston put down his weapon to load the money into a cooler he had brought with him, one of the employees grabbed the gun, police said.

Once he was disarmed, the second employe jumped Preston and additional employees rushed in, eventually pinning Preston to the ground. During the tussle Preston told employees he had a bomb strapped to his chest, threatening to blow the establishment up and everyone in it, Nashua Police Lt. Denis Linehan told ABC News said.

While his dad was inside trying to rob the hall, Justin Preston stood outside as a lookout, but his suspicious behavior attracted the attention of a police officer, the lieutenant said.

"Justin was wearing dark colors" and had the hood of his sweatshirt over his head, .. The officer decided to stay in place to further monitor him, Linehan said.

Another employee called 911 at 8:35 p.m., and the officer monitoring the younger Preston heard the call and rushed inside. Other officers in the immediate area were able to respond quickly to the scene as well for back up, Linehan said.

According to the police report, Justin's father was found "inside the business and being restrained by several employees."

Charles Preston is charged with armed robbery and false report of an explosive device. Justin Preston is charged with criminal liability to an armed robbery.

No explosive devices were found.

They are being held at the Hillsborough County Department of Corrections. They were arraigned on Monday and pleaded not guilty. Justin Preston is being held on $25,000 cash bail and father Charles is being held for $75,000 cash.

The Eagle's Wings Function Hall was hosting a bingo night for the Blessed John Church out of Merrimack, N.H. There were approximately 300 people in attendance at the time of the robbery.