Jason Eric Howell, 40, is facing charges of murder, attempted murder, hindering prosecution and concealing a dead body.
According to the report, 78-year-old Helen Jean Lee's daughter called Goodyear police because she had not heard from her mother in a while. Howell was reportedly living with Lee.
In the court document, it was noted that Goodyear police had extensive history with Howell at the residence for calls such as hallucinations, erratic behavior and violent tendencies. There was also a history of Howell taking medication for schizophrenia.
The first officers to arrive found the garage door severely damaged and Lee's 2006 Honda Odyssey missing.
Police were not able to reach Howell or Lee, however the suspect's phone indicated its user was west of Gila Bend. His grandmother was then listed as an endangered missing person.
Howell was arrested the same day following a
police pursuit in Chandler . In that incident, he allegedly stole a car from a Chandler elementary school and rammed several police vehicles during the chase.
Chandler police told Goodyear officials that Howell had made a "spontaneous statement" that he had killed his grandmother.
Howell reportedly told police he killed Lee because he was upset with her strict curfew rules. He also said Lee had broken the garage door and he was upset over it, and that his grandmother charged him too much in rent.
Howell told police he had tried to kill his grandmother a few days earlier while she slept but she awoke as he was about to strike her in the head with a heavy object, according to the documents.
He reportedly said he killed Lee a few days later by striking her in the back of the head with a shovel two or three times, then cut her throat as he held her from behind.
Police said Howell told them he waited two days then got rid of Lee's body in the desert west of Gila Bend.
Investigators were led to a remote site about 19 miles west of Gila Bend where they found Lee's body.
Authorities said she had a skull fracture the size of a baseball and her throat had been "cut from ear to ear, nearly decapitating her."
Police said Howell has repeatedly threatened suicide and escape since his arrest.