A Mom Didn’t Show Up to Her Birthday Party. Then Police Found Her Decapitated, and Suspect Is Her Son

An Arizona man was arrested after he allegedly killed his mother, who was found decapitated inside her home after not showing up for her surprise birthday party that same day, authorities say.

Alejandro David Gonzalez, 25, was arrested on Sept. 28 on charges of first-degree murder and theft of means of transportation in connection with the killing of his mother, 49-year-old Teresa DeJesus Cruz Rubio, according to a press release from the Glendale Police Department. 

He was being held in the Maricopa County Jail, per the release. It’s unclear if he has entered a plea or retained an attorney to speak on his behalf.

On Friday, Sept. 27, at around 11:45 p.m. officers responded to a Glendale, Ariz., apartment to conduct a welfare check after Rubio’s sister called 911 saying she found the woman dead and that her head had been cut off, Glendale Police Sgt. Bryan Hoskin said at a Monday, Sept. 30 press conference.

According to a probable cause statement reviewed by PEOPLE, authorities said Rubio’s body was underneath a blanket with her decapitated head nearby and that there was blood throughout the home. Police said she suffered multiple stab wounds to her abdomen, chest and arms, adding that an autopsy will be conducted. They also said there were no signs of forced entry into the home.

Rubio’s sister said that the family had arranged a surprise birthday party for Rubio, and that Rubio had previously confirmed her attendance for what she believed would be a “family gathering” that day, according to the probable cause statement. However, as the hours passed, Rubio still hadn’t shown up and wasn’t answering her calls, and her sister became concerned. So she said she went to her sister’s home, where she made the grim discovery, per the statement.

Family members told police that they believed Gonzalez, Rubio’s son, had recently been released from jail and was living with her, according to the probable cause statement. They alleged to police that Gonzalez had “mental conditions” and was “capable of killing” Rubio, the statement reads. (PEOPLE couldn’t immediately confirm details regarding Gonzalez’s previous jail stint.)

According to the probable cause statement, Rubio’s sister also told investigators that she allowed her sister to borrow her burgundy GMC Yukon, which was missing. Authorities said surveillance video showed the SUV driving away from the apartment earlier that day with a man believed to be Gonzalez behind the wheel.

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The next morning, at about 2:40 a.m., a Phoenix police officer spotted the GMC Yukon at a gas station, according to the probable cause statement. There, police reported seeing Gonzalez coming and going from the SUV and took him into custody a short time later. Police alleged he had what appeared to be dried blood on his legs and socks.

According to the probable cause statement, Gonzalez said during questioning that his mother had recently picked him up from jail, got him food and dropped him off at her apartment. He allegedly admitted to “smoking methamphetamines” with a man he just met, whom he claimed did “something” to his mother, the statement reads. 

Gonzalez allegedly said the man stabbed his mother with a kitchen knife and that he only stabbed her — and decapitated her — after the man had already stabbed her, per the statement.

At this point in the investigation, authorities do not believe there is enough evidence to suggest that Gonzalez had an accomplice, according to the probable cause statement.