Brent Alvarez runs Twisted Web MMA in Eugene, Ore., and Billy Denney is his student. They were walking through the hotel lobby when they saw the robber, who had gone behind the hotel's counter, pulled out a gun, and demanded money. The clerk handed over the cash, but yelled for help. Alvarez and Denney jumped on the robber, and while Denney controlled his wrists, Alvarez sunk in a rear naked choke. They held him in place until police arrived.