Charles Augusto Jr., 72,

A day after shooting four men who tried to rob his restaurant supply store, killing two of them, Charles Augusto Jr., 72, was back at work in Harlem on Friday morning. His feelings the day after he pulled the trigger? “I wish I didn’t need to,” he said.

Mr. Augusto, who goes by Gus, opened the shop, the Kaplan Brothers Blue Flame Corporation, at 523 West 125th Street, near Amsterdam Avenue, at 8 a.m. He was accompanied by an employee who had been hit with a pistol during the robbery Thursday afternoon. After the employee was struck, Mr. Augusto picked up his shotgun and fired it three times.

The shots killed two men, James Morgan, 29, and Raylin Footman, 21, and wounded two others, Bernard Witherspoon and Shamel McCloud, both 21, the police said. The two survivors are being charged with robbery, the police said.

Mr. Augusto said he had bought the gun, a Winchester 12-gauge pump-action with a pistol-grip handle, after a robbery 20 years ago and had a permit for it. “Not even touched in 20 years,” he said. “Not even touched. I wish I didn’t need to.”

The employee, who goes by J. B. and declined to give his last name, said that he “lost my mind” while the robbers tried to restrain him with duct tape, and that when he struggled, he was hit with the pistol. “Better him with a tag on his toe than my mother planning a funeral for me,” he said of the gunman.