A 92-year-old woman in the US has shot and killed her son because he wanted to put her into a care home.

Arizona police said Anna Mae Blessing was arrested on suspicion of murdering the 72-year-old man, and was being held in lieu of $500,000 ($677,000) bail, court officials said.

Ms Blessing told detectives following her arrest that she had confronted her son about his intentions to put her in the care facility because, he had said, she was difficult to live with.

She told detectives she hid two handguns in the pockets of her robe and confronted her son in his bedroom, shooting him with multiple rounds, the Maricopa County Sheriff’s Office said in a written statement.

Ms Blessing told investigators she tried to point the guns at her son’s 57-year-old girlfriend but the woman was able to wrestle the weapons away, according to the sheriff’s office.

She was sitting in a reclining chair in her bedroom when she was taken into custody, after she refused to leave the house in suburban Phoenix, according to court records.

Ms Blessing also told detectives that she should be “put to sleep” for her actions and had intended to kill herself following the incident.

She said she purchased one of the weapons and the other one had been given to her deceased husband. Neither weapon had been fired since the 1970s.

Police said they had visited the house before, following an argument between Ms Blessing and her son.

-with Reuters