Arizona mother decapitated by her son hours before her surprise birthday party, police say

GLENDALE, Ariz. - A woman's decapitated body was found inside a Glendale home and her son was arrested in connection to the gruesome death, police said.

An investigation began on Friday, Sept. 27, just before midnight near Bethany Home Road and 43rd Avenue when a family member called to report finding 49-year-old Teresa DeJesus Cruz Rubio dead.

"The family had prepared a surprise birthday celebration for the victim. Earlier that day at around 3:40 PM, family members contacted the victim, who had agreed to gather with them. When the victim failed to show up to the gathering, the family became concerned and went to her home where they discovered her decapitated body," Glendale Police said.

Investigators had reason to believe the victim's son, Alejandro Gonzalez, was involved in his mother's death.

Gonzalez reportedly was using his mom's car around 5 p.m. that day. Not long after that, he reportedly used his mom's phone to call family members.

The car was found by Phoenix Police at 2:40 a.m. on Sept. 28 near 99th Avenue and I-10. Gonzalez was taken to the Glendale Police station for questioning.

"Alejandro admitted to stabbing his mother numerous times using a kitchen knife, followed by decapitating her," police said.

He was booked into the Maricopa County Jail and is accused of first-degree murder. His bond is set at $1 million, cash only.

The family told officers Gonzalez had just gotten out of jail and was living with his mom. Court paperwork reveals his family said he had mental conditions and was capable of killing her.

Cruz Rubio was a beloved teacher at Southwest Key programs.

Teresa DeJesus Cruz Rubio and Alejandro Gonzalez

'It’s absolutely horrific'

Police say it was Cruz Rubio's sister who was the last to talk to her late that afternoon. She was calling her to confirm what would have been her surprise birthday party.

With the help of a lock smith, the family got into her home and found her dead.

Sgt. Bryan Hoskin of the Glendale Police Department says officers found Cruz Rubio under a blanket with multiple stab wounds on her body.

"The 9-1-1 caller stated a family member was inside the house, was deceased, and that the victim’s head had been cut off," Sgt. Hoskin said.

Officers noticed the shower was still running, and a bloody kitchen knife was in the sink.

Her sister told officers her burgundy GMC Yukon she gave to Cruz Rubio to use was missing. FOX 10 obtained video of the SUV captured by a neighbor’s Ring video leaving the home in the late afternoon.

When police found the SUV and Gonzalez, they reportedly saw injuries on his hands and arms, and blood on his clothes.

"Alejandro also spoke in the investigation and interview about using methamphetamines. Alejandro claimed there was another suspect involved, but detectives said no other evidence pointed to this as they were going through the scene with all the other evidence collected," Sgt. Hoskin said.

Glendale PD says the victim advocacy center is assisting the family and officers to help process the trauma of such a horrific sight.

"It’s absolutely horrific. It’s horrific to the family who had to endure this, it’s horrific to the officers who had to go and see this," Sgt. Hoskin said.