DECATUR, Ga. (NEXSTAR) – A triple shooting at a Georgia grocery store Monday afternoon started with a dispute over a mask and left a cashier dead and both the suspect and a deputy wounded, authorities say.

The suspect, 30-year-old Victor Lee Tucker, Jr., of Palmetto, Georgia, was checking out when he got into an argument about his mask with a female cashier at Big Bear Supermarket in Decatur, according to the Georgia Bureau of Investigation.

DeKalb County police identified the victim as 41-year-old Laquitta Willis.

Tucker walked out without buying anything but immediately returned, pulling out a handgun and allegedly shooting the cashier shortly after 1 p.m. She was rushed to an area hospital where she was pronounced dead.

One of several people in the store at the time of the shooting was a 30-year DeKalb County Police Dept. veteran now working with the sheriff’s office as a reserve deputy, DeKalb County Sheriff Melody Maddox said.

The off-duty deputy, who was providing security for the store at the time, shot the gunman but was hit twice during the exchange of gunfire, according to the GBI. The bulletproof vest he was wearing likely saved his life, Maddox said.

“This is what he is trained to do,” Maddox said. Reserve deputies are certified law enforcement officers who don’t actively work for an agency and can volunteer or work part time security jobs.

The officer, who authorities didn’t publicly identify, is being treated at Atlanta Medical Center and was in stable condition at the Monday afternoon.

“He is a stand-up, professional individual and he loves what he does,” Sheriff Maddox said. “As you see, he’s continuing to do what he does to make sure that everybody is safe as they go in and out of that store.”

Dekalb County police officers arrested Tucker as he tried to crawl out of the grocery store, according to the GBI. Tucker was hit “a couple of times” Maddox said and was taken to Grady Memorial Hospital in stable condition.

A bullet grazed a second cashier who was treated at the scene for her injury, according to the GBI.

The GBI’s investigation was still ongoing Monday evening and will be turned over to the DeKalb County District Attorney’s Office for review once investigators have finished.

Decatur is an Atlanta suburb located about 6 miles east of downtown.