The victim was hospitalized in stable condition.
Police Sgt. Cameron Hokenson said Daniel Pirtle, 45, who has metal prosthetic legs and was driving a motorized shopping cart, became involved in a dispute with Walmart Assistant Manager Jason Mahi, 33, in Anchorage Saturday.
After being told he had to remove his unrestrained service dog from the store, Pirtle allegedly brandished a handgun and shot Mahi in the midsection, the Anchorage Daily News reported Saturday.
"They were escorting him out of the store and something happened on the way out where the suspect pulled out a weapon and shot the employee," Hokenson said.
Mahi underwent surgery for his injury, the newspaper reported.
Pirtle was charged with first-degree assault and fourth-degree weapons misconduct. He was being held on $50,000 cash-only bail, police said.