WALKER COUNTY, Ga. — In a case that could renew the debate over stand-your-ground laws, authorities in northwest Georgia say one man shot and killed another after the shooter felt threatened by a 72-year-old who turned out to be a wandering Alzheimer’s patient.Walker County authorities told the Chattanooga Times Free Press (http://bit.ly/1bXSw3m ) that the victim, Ronald Westbrook, walked about three miles in the sub-freezing temperatures before knocking on Joe Hendrix’s door just before 4 a.m.