Robert Dwyer, a counselor at the Federal Correctional Institution in Danbury, has trained with 9 mm handguns every year in his other role as a weapons instructor for the Department of Justice.

So he knew just what to do when an assailant approached him Tuesday night outside his Waterbury home brandishing a handgun.

The man had followed him from a bank automated teller machine about a mile away from his house, Dwyer said.

He noticed something was amiss when he pulled into his driveway and saw another car speed down a dead-end side street. From there, things got interesting.

"Somebody was walking down the street," Dwyer said Friday. "All of a sudden he started saying 'Yo, yo.' Then he comes on up and pulls a 9 mm out and says, 'This is a robbery, yo.'"

That's when Dwyer's expertise with weapons kicked in. "I reached down and grabbed the gun by the upper receiver," he recalled.

A struggle ensued, during which a shot was fired that did not hit either man. Dwyer said because of the way he grabbed the gun, the spent shell casing could not be ejected from the chamber, and the gun jammed.

Not that he knew that.

"At that point I wasn't exactly sure. I didn't know the gun wasn't working at that time," he said.

So as his struggle with the would-be robber, later identified by police as 25-year-old Eddys Marte, spilled into the street outside his home and Marte was able to get away from him momentarily, Dwyer sought cover behind a car, fearing he could be the target of a gunshot.

But by then, his two sons, Robert Jr., 27, and Christopher, 25, had heard the commotion and left the house to come to his aid.

Christopher tackled Marte, Dwyer said, and he and Robert Jr. subdued the assailant and kicked the gun away while a neighbor called police.

"My children got into the fray, so I had to get back into the fray," he said.

After officers took Marte into custody, he was charged with a bevy of crimes -- attempted first-degree robbery, attempted first-degree assault, first-degree reckless endangerment, illegal discharge of a firearm and carrying a pistol without a permit.

He was arraigned Wednesday in Waterbury Superior Court and ordered held in lieu of $600,000 bond. He is now behind bars at New Haven Correctional Center.

Dwyer, who also served eight years in the Army before his career in corrections began, was thankful Friday for his familiarity with 9 mm guns, but said he never thought he'd get the kind of hands-on experience he did Tuesday.

"We shoot and I train with them each year," he said. "In some of my training I've had classes in weapons retention and disarming somebody if they get your weapon."

Bill Katzing, his supervisor, commended Dwyer's heroics Friday, saying in an e-mail it was "hard to believe this actually happened."

"I can't tell you how proud I am of Bob and what he did," Katzing noted. "This man is a law enforcement professional and is a true hero."

Though glad everything worked out OK, Dwyer said Friday the entire incident could have been avoided were the assailant more discerning in choosing potential victims.

"I drive a Daewoo," Dwyer said. "I would've looked for a better car than mine."