Inset: Zachary Parker (Maricopa County Jail via KPHO). Background: Hatfield Road in Peoria, Arizona (Google Maps).

A 25-year-old Arizona man allegedly shot his stepfather to death before walking out of the home and telling cops “he did what he needed to do.”

Zachary Parker is facing charges of second-degree murder and aggravated assault following the death of 64-year-old Casey Orlowski at their residence in Peoria, a suburb of Phoenix. Police were dispatched shortly before 10 p.m. on Sunday to a property on Hatfield Road near 83rd Avenue and Happy Valley Road after Orlowski reported that Parker had aimed a firearm at him and his wife multiple times, as mentioned in a press release from the authorities.

Orlowski informed that he had secluded himself in a bedroom and was unaware of the whereabouts of his wife and stepson. The police received a follow-up call from Parker’s mother, who had fled the house and sought refuge at a neighbor’s residence. As officers arrived on the scene, they heard multiple gunshots coming from inside. It was reported in an arrest affidavit by local CBS affiliate KPHO that Parker called 911 claiming that his mother was dying and alleged that his stepfather was associated with a cartel and attempted to murder him.

Officers apparently tried to force entry, but a metal door was blocking their way. Shortly thereafter, Parker reportedly came out with his hands up.

Parker allegedly informed the police that “he did what he needed to do.” He was subsequently detained by the officers. Inside the home, authorities discovered Orlowski deceased from gunshot injuries in a bedroom, with indications that Parker had fired through the bedroom door, according to the affidavit.

Police say Parker had a history of mental health problems and had access to firearms.

Parker is currently held at the Maricopa County Jail. At his initial court hearing, Parker asserted that his stepfather was the aggressor and that he shot him in self-defense, as reported by KPHO.