I guess you didn't read the article. The store is constantly robbed of beer. Beer costs money and the continued loss of beer would eat into a convenience stores profit since that is one of their biggest money makers. Their very lively hood depends on it. Plus the clerks were being threatened by some of the thieves.
You can't just let people come in off the streets and take your products, a store owner must be able to use what force is necessary to stop this kind of theft. Police were unwilling to act on the thefts according to the store owner and I would imagine the clerk had just finally had it.
As far as I am concerned this was a justified shooting. If a cop had been on the scene he could have shot and killed the perp while he was running away and it would have been a "good" shoot. Let a citizen do it in defense of their property however and suddenly it is murder.
“If a cop had been on the scene he could have shot and killed the perp while he was running away and it would have been a “good” shoot.”
That may have been true 50 years ago, but not today. These days I’m not sure a cop can shoot a non-violent fleeing felon, let alone a petty thief.