To the observant eye, there were clues the bank robbery taking place in the wooded suburbs of northwest Austin was a spur-of-the-moment idea.

For one thing, the black mask the robber wore, along with the harmless black air pistol he gripped, were designed for the sport of paintball. And this branch of Regions Bank near Lake Travis was only a few miles from a paintball field, whose offices were down the street.

“Don't play,” he told the teller. “Don't set off any alarms. All big bills.”

And when police captured him minutes later at a car wash in August 2008, guided by two tracking devices stuffed into his bag by the bank supervisor along with $18,805 in cash, they discovered this was no typical bank robber, either.

Dr. John Christian Gunn of San Antonio was a handsome, 45-year-old cardiothoracic surgeon, a graduate of Yale Medical School, an athlete who once qualified for the Hawaii Ironman Triathlon. He was a Marine veteran and the captain of his college football team.