Gun rights advocates often argue that armed residents can help thwart crime. But law enforcement officials say that at least twice in recent days, armed bystanders have gone a big step beyond that, shooting at fleeing shoplifters who posed no immediate danger.

On Tuesday, prosecutors charged a woman with a misdemeanor for firing at a getaway vehicle in the parking lot of a Home Depot in Auburn Hills, Mich. And the police in Elkhart, Ind., said they were looking into whether to bring charges against a man who did much the same thing there on Monday. No one was hurt in either shooting.

In each case, the person with the gun was a customer who was licensed to carry a concealed weapon, saw store employees chasing shoplifters and fired as they drove off. In the Michigan case, the Oakland County prosecutor, Jessica R. Cooper, charged Tatiana Duva-Rodriguez with one count of reckless use, handling or discharge of a firearm.

“If this is proven, I find it very disturbing that someone would take out their gun in a busy parking lot and shoot at the tires of a passing car,” Ms. Cooper said. “Once fired, the bullet could have easily ricocheted or fragmented and injured or killed someone else.”