(AP) -- A Sun City man accused of fatally shooting his ailing 81-year-old wife has pleaded guilty to manslaughter.
Maricopa County prosecutors say George Sanders, 85, entered his plea Tuesday.
They say Sanders could face either probation or up to 12 1/2 years in prison when he's sentenced March 29.
He originally pleaded not guilty to a charge of first-degree murder.
Virginia Sanders was found shot in the head in the couple's home last Nov. 9 and died two days later in a hospital.
George Sanders told authorities it was a "mercy killing" because his wife had been suffering from multiple sclerosis for years and was in diminishing health.
He says his wife asked him to kill her because she didn't want to spend the rest of her life in a nursing home.