Anna Mae Blessing was arrested after opening fire on her son Monday, allegedly because he wanted to put her in an assisted living facility.
Blessing had been living with her son and his girlfriend for the last six months, when on Monday she began arguing with him over the way she was being treated, court records state.
Blessing told detectives she got out two handguns she has had since the 1970s -- one bought at a gun store and the other obtained from her late husband.
Records show Blessing concealed her two pistols in the pockets of her robe before confronting her son in his bedroom and firing multiple shots at him with one handgun.
The gun was dislodged from Blessing's hand after a struggle with her son's girlfriend, as well as the second weapon, authorities said.
The unidentified woman called authorities and Blessing was located on a recliner in the home and taken into custody.
Court documents stated the Monday incident was not the first time authorities had to intervene between Blessing and her son. Maricopa County Sheriff Paul Penzone said deputies had responded to four or five calls at the residence in recent weeks after disputes were reported between the pair.
Barbara Blessing, Anna Mae's granddaughter and the daughter of the victim, tells ABC15 her father had tried to get police to take the 92-year-old's guns away, but police reportedly said she had a right to have them.
Penzone at a Thursday news conference said deputies also found 11 other firearms, which belonged to the victim, accessible around the residence. MCSO is now reviewing all calls of service to the Fountain Hills home to ensure responding deputies acted properly, he said.
Barbara, meanwhile, says she believes her grandmother needs help, not to be put behind bars.
"All I want to do is get her out of that jail where she can have her dignity back and get medication she needs so she can rest in peace," Barbara tells ABC15. "She doesn't deserve to be treated like this, she's not well, she's very ill."
Blessing has been charged with a count of murder in the first degree, a count of aggravated assault with a deadly weapon, and a count of kidnapping.