Steinmetz received national attention in July after walking around Sky Harbor with an AR-15 slung over his shoulder during a self-described coffee run.

While bringing the gun to the airport is not illegal, Steinmetz was arrested on suspicion of two counts of disorderly conduct after the gun's muzzle reportedly faced toward a frightened woman and her daughter, according to Phoenix police. Barrow put Steinmetz on a brief administrative leave, having returned to work a week later, he said Tuesday.

Steinmetz said his trip to the airport was peaceful until the police decided to arrest him and that few people noticed he had a gun as he walked through one of the airport's busiest terminals.

Marc Victor, Steinmetz's lawyer, said the county attorney's decision validated his client's actions and proved that he never broke the law.

"To charge him with a crime when he didn't commit a crime would be outrageous," Victor said. "And so it's a fair and reasonable result because it doesn't put any kind of requirements that are onerous on my client."

Victor said airport surveillance video shows that Steinmetz was carrying his gun peacefully and legally.

"He didn't go there with the intent of disturbing anybody's peace," Victor said. "He wasn't aware of disturbing anybody's peace. And he never recklessly displayed a firearm."

Steinmetz said he did not expect the media attention that came with his actions, but he doesn't regret what he did.

"I think it was a worthwhile endeavor, and I think it has made the point fairly powerful," Steinmetz said.