A woman in the US is facing murder charges after allegedly shooting her son who tried to put her in a nursing home.

Police in the state of Arizona say 92-year-old Anna Mae Blessing shot and killed her 72-year-old son.

Maricopa County Sheriff’s deputies responded to a call at a house on Monday.

According to statements provided by Blessing and received by the detectives, she had been thinking about her son's intentions to place her in an assisted living facility for several days.

Blessing had taken two guns and concealed them in the pockets of her dressing gown.

She then confronted her son in his bedroom.

During the confrontation, she told police she removed the handgun and fired multiple rounds, striking and killing her son.

She then pointed the gun at her son's girlfriend, and the two struggled over the weapon.

Blessing then got the second handgun and attempted to point it at the girlfriend, who knocked it from her.

The girlfriend contacted police who responded and took Blessing into custody.

Sheriff Paul Penzone said: "It is always concerning when domestic issues escalate to violence or tragic outcomes.

"They are often isolated and neither predictable nor preventable."

Blessing was charged with one count of murder in the 1st degree, one count of aggravated assault with a deadly weapon and one count of kidnapping.