According to the Michigan State Police, an argument between two men began over wearing a mask inside the Quality Dairy Store in Dimondale, Michigan.
The argument continued in the parking lot, where investigators say Sean Ruis, 43, of Grand Ledge, Michigan, stabbed a 77-year-old man during the dispute, police said.
Ruis, who was not wearing a mask, then drove away to a nearby neighborhood, police said.
The stabbing victim, who had been wearing a mask, was treated for his injuries.
Ruis was later stopped by an Eaton County Sheriff’s deputy.
Ruis pulled a knife on the deputy, who then shot him, authorities said. He died from his injuries.
According to earlier reports, gunshots were heard in the area just after 9:00 a.m.