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 stands accused of second-degree murder and aggravated assault in the death of 64-year-old Casey Orlowski at their home in Peoria, a Phoenix suburb. Cops responded just before 10 p.m. Sunday to a home on Hatfield Road near 83rd Avenue and Happy Valley Road after Orlowski called to say Parker pointed a gun at him and his wife several times, the agency said in a press release.

The victim said he had locked himself in a bedroom and did not know where his wife and stepson were. Cops received a second call from Parker”s mother saying she had escaped the home and ran to a neighbor’s home for help. As officers arrived at the home, they heard several gunshots from inside. Parker called 911 to say his mother was dying and his stepfather was a cartel member trying to kill him, according to a probable cause arrest affidavit obtained by local CBS affiliate KPHO.

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 reportedly told officers “he did what he needed to do.” Cops took Parker into custody. They went into the home, where they found Orlowski dead from gunshot wounds in a bedroom. Parker apparently fired through the bedroom door, the affidavit reportedly said.

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

Parker remains at the Maricopa County Jail. During his first appearance, Parker claimed his stepfather was the aggressor and he shot him in self-defense, KPHO reported.