George Bannerman was the sheriff in Castle Rock, Maine from November of 1972 until his death in July of 1980. He has a wife named Vicky and a daughter named Katrina. He also has an Irish Setter dog named Rusty who was living during the events of The Dead Zone, but had been put down by the events of Cujo. He is described as being a very large man with dark, curly hair, and wears rimless spectacles.
He was killed by the rabid dog Cujo.
According to Mike Noonan in the novel Bag of Bones, the Castle County Sheriff in August of 1901 was Nehemiah Bannerman. Although it isn't stated outright, it is likely that Nehemiah and George were relatives.