just ask lloyd irvin. >> i'm laying on the couch. i wake up and there's two gunmen over top of me holding guns, pointing 'em at me, like, holding down. you're being robbed. don't move. >> reporter: more than six years have passed since that night in august 2008, here outside the nation's capital in a nice neighborhood in prince george's county, maryland. but lloyd and his wife vicki and their son -- just four years old at the time -- are still haunted by the image of the gunmen. two masked intruders. talk about your worst nightmares. this is it. >> yes. it's something you would never imagine would happen. >> reporter: what the robbers didn't count on was that lloyd is a nationally-renowned martial arts expert. and when one of the gunmen walked away to scope out the rest of the house, lloyd was suddenly one-on-one with his accomplice. gunman's over here in the corner, huh? >> right in the corner right there. i know he doesn't have any room to back up at all. i just go. i'm coming over here, and i got the gun. i'm trying to get the car