A city commissioner in Florida was charged on Friday with second-degree murder after fatally shooting a man he suspected of stealing a hatchet from his shop.

The grand jury indictment came about two weeks after the commissioner, Michael Dunn, 47, of Lakeland, Fla., confronted a man and then shot him with a handgun as the man was leaving the store. The man, Christobal Lopez, 50, died at the scene.

Brian Haas, the state attorney for the 10th Judicial Circuit, said in a statement that Mr. Dunn’s actions fell outside the protection of Florida’s Stand Your Ground law, which can make it challenging to prosecute people who maintain they killed someone in self-defense.

Mr. Dunn is a co-owner of an Army-Navy surplus store, which carries a selection of firearms, military surplus and public safety supplies. He began serving a four-year term as an elected city commissioner in January in Lakeland, which is about 35 miles east of Tampa, Fla.