PRINCETON, W.Va. (AP) - Authorities say a West Virginia man with signs of Alzheimer's fatally shot his wife when he thought she was in distress.

The Bluefield Daily Telegraph reports 65-year-old Larry Dillon shot his wife, Sandy Dillon, in their home on Thursday night.

Mercer County Prosecuting Attorney George Sitler says there is evidence that Dillon has Alzheimer's disease, a cognitive disorder. Dillon has been charged with first-degree murder, but a judge has ordered that Dillon undergo a mental competency hearing.

Police say Dillon believed family members were being harmed, so he took out a handgun and began shooting in a bedroom with his wife and 9-year-old granddaughter inside.

Prosecutors say if Dillon is found to be mentally incompetent to stand trial, he could end up in a state psychiatric facility.