Roy Charles Laird, 88, killed his wife Clara, 86, Sunday with a single gunshot to the head at the Country Villa Health Care Center in Seal Beach, police told the Los Angeles Times.
"It was a mercy killing," said their daughter, Kathy Palmateer, 68. "Her mind was gone."
As Clara Laird declined steadily from dementia over five years, her husband cared for her himself at home until three months ago. He would visit her at the nursing home three times a day, spoon-feeding her at each meal, friends and family said.
Around noon Sunday, a single gunshot was heard at the nursing home. Within minutes, police surrounded it and called in backup.
"We didn't know if we had a shooter or not," said Seal Beach police Sgt. Steve Bowles.
Police found Clara Laird dead in her bed and her husband in the hallway. He followed them into her room, took a .38-caliber revolver out of his pocket and calmly set it on a table, Bowles said.
Laird was arrested on suspicion of murder.