McMinn County authorities say longtime Calhoun volunteer firefighter Dennis Patterson was killed Sunday by his wife's live-in nephew as he was mowing his yard.
Sheriff Joe Guy said Jason Paul Baker, 32, lived at 4696 U.S. Highway 11 South, Riceville, with Patterson, 60, and his wife, Lois, since he was recently released from prison.
An argument of some kind led to violence after Lois Patterson had to leave for work on Sunday, Guy said.
A neighbor called authorities around noon Sunday about shots being fired at the home where responding deputies discovered Patterson's body in the yard and blood-covered Baker on the scene, he said.
Baker is charged with first-degree murder and is being held without bond, according to authorities.