The judicial system does not execute criminals for stealing, burglary, armed robbery, car jacking, etc. That is ENTIRELY different than a victim of a crime being able to use any force necessary to neutralize a threat, which is what the clerk did. He didn't stab him for theft, he stabbed him because he jumped the counter and posed a danger to the clerk. Further, there seems to be no evidence that the robber died. That piece of shit punk could have had a gun, for all the clerk knew, so he had no choice but to stab him until out of commission and no longer posed any possibility of a threat. This is not complicated for anyone with two brain cells to rub together.