A 34-year-old Chattanooga man shot and killed a 72-year-old man who rang the doorbell around 4 a.m. today at a home in a new subdivision off North Marble Top Road in rural Walker County, Ga., Sheriff Steve Wilson said.

At a news conference this afternoon, Wilson identified the shooter at the house on Cottage Crest Court as Joe Hendrix of Ooltewah and the victim as Ronald Westbrook of Walker County.

Wilson said the victim, who had advanced Alzheimer's disease, had been walking around for about four hours and almost three miles before the incident occurred. He said Westbrook was lost and rang the doorbell and turned the door handle at the home, where Hendrix was visiting his fiancee.

The woman, who was not identified, called a 911 dispatcher and was on the phone with that person when Hendrix took a 40-caliber handgun outside and confronted the victim in the yard behind the home, the sheriff said.

Westbrook apparently did not respond to commands from Hendrix because his condition has left him essentially mute, the sheriff said.

Hendrix fired four shots, one of which struck the victim in the chest and killed him.

The victim's body was removed around 10:30 a.m., and the shooter was allowed to drive off in his own vehicle.

Wilson said District Attorney Herbert "Buzz" Franklin, who was called to the shooting scene this morning, will determine whether any charges will be filed against Hendrix.

The couple moved into the home about two weeks ago, next-door neighbor Brandi Wallace said.

Wallace's family was awakened by the gunshots.

For complete details, see tomorrow's Chattanooga Times Free Press.