The shopkeeper shot the thief in the back as the thief was fleeing on a motorbike. Odd that the Blaze does not mention that detail. Or maybe it's not so odd.
Anyway, I'd have a hard time convicting the shopkeeper. He was terrified, I'm sure. And it was not the shopkeeper who put all of this in motion. It was the thief.
From the Wall Street Journal:
http://online.wsj.com/article/SB10001424127887324492604579084873062376790.html
Mr. Turk told the police that he shot twice at the motor scooter in an attempt to immobilize it, and it was only when one of the robbers turned to him in a threatening way with his automatic weapon that Mr. Turk shot him dead.
So it's not quite as cut and dried as shooting a fleeing robber in the back, although I certainly wouldn't recommend the "shoot out the tires of your fleeing attackers" strategy as a self defense tactic.
I don’t have a problem with shooting the criminal in the back while he is running away. He still committed the crime and we are supposed to let him run away? Not in my opinion.