An Arizona woman had contemplated killing her mother years before smothering her with a pillow on Monday and setting a bottle of gin on the dead body, according to court documents.

After Holly Brennan, 46, had used a pillow to suffocate 79-year-old Sharon Simmons, she walked to a convenience store and bought two bottles of liquor — vodka for herself and gin for her mother, Arizona Central reported, citing court documents. Police found Simmons in a bedroom with the alcohol bottle on her stomach and a pillow partially covering her face.

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The documents claimed Brennan had called Scottsdale police twice around 2 p.m. after her mother’s death.

"My name is Holly, and I need police here," she initially said.

Brennan then called a second time and reportedly said, "I killed my mom." When police asked Brennan how her mother died, she allegedly admitted to "smothering" her.

Brennan threatened to kill her mother on at least two occasions — once in a 2017 Facebook post, which later led to her arrest, and again in 2018, according to the documents. At that time, however, she sought treatment.

The 46-year-old reportedly detailed her actions in an interview with police after being taken to the Maricopa County Jail. Brennan said she pushed the 79-year-old onto her bed, climbed on top of her and pressed a pillow to her face, according to Arizona Central.

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She said she had decided to kill her mother mere minutes before doing so, according to the documents.

Brennan will face a charge of second-degree murder, the paper reported.