It’s the absolute worst nightmare of peaceful people come alive, right before our very eyes, in bright daylight.

When Wisconsin foolishly passed a concealed carry bill, there were many people – me among them – who predicted that this was going to spawn a kind of vigilante justice and turn many neighborhoods into the OK Corral.

Well, Guess what? It’s happened.

I read about this incident last week, but it happened on the last day of 2012.

A guy named Michael Simpson had been shopping near 76th and Capitol, one of the busiest intersections in town. Simpson got held up but a guy with a gun. First he told the robber he didn’t have anything. Then, upon further urging by the gunman, Simpson gave him everything in his pockets. The robber took off.

But instead of saying a prayer and thanking his lucky stars he was alive, he followed the gunman. He told police that when the gunman noticed he was being followed, he turned toward Simpson and pointed his gun. That’s when Simpson let loose with a volley of seven shots at Devonte Capre Harris, the alleged thief.

They exchanged shots in the early afternoon light and then Harris ran into a store, saying he had been shot. The police came and took Harris to a hospital and they found his gun and Simpson's stuff in a nearby trash can.

It almost leaves you breathless, doesn’t it?

I’m not sure where to start, but I think with Simpson would be a good place. How in the world does someone with that kind of attitude ever get a permit for a gun, much less the ability to carry a concealed weapon?

What would we all be saying if one of his misses had accidentally killed some innocent bystander? Killed a child? Would all these gun nuts say something like, "well, collateral damage is sad, but it happens in a gunfight. He was just protecting himself."

He wasn’t protecting himself. The crime was over. The thief was running away. There is no property worth killing someone over. Not property. Not things. Not money. Nothing. Simpson was out of danger. But with a gun in his hand he was apparently anxious to put himself, and who knows how many others, back into danger.

Kent Lovern is the assistant district attorney who examined the case. He said Simpson's actions were justified under the circumstances. Lovern is a top aide to DA John Chisholm and a guy who has a reputation as a very good and very smart lawyer.

I wanted to find out what those circumstances were that made it okay for Simpson to unload on Harris d so I called Lovern.

"The report is clear that Harris fired at Mr. Simpson," Lovern told me. "And once that happened Mr. Simpson had the right to fire back and protect himself."

Lovern is smart enough and savvy enough to avoid being pulled into any discussion about the decision Simpson made to go after Harris in the first place. I respect Lovern for that.

But holy cow, is there any way that anyone with an ounce of common sense can’t see the danger here. I mean the potential danger to people walking out of a store or standing by a bus stop.

I know, I know. None of this would ever have happened if the bad guy hadn’t robbed Simpson. But robbery happens. We are never going to stop all of the robberies. But to turn a robbery into a gunfight is just crazy dangerous. Or maybe it’s just crazy.