Peoria Police arrested Shaun Gentilo and charged him with fatally stabbing his step-grandfather.
Police responded to a stabbing call at 3 a.m. April 24 on the 9200 block of West Gold Dust Avenue.
Police found the victim, an 89-year-old Peoria resident, who died at the scene.
Gentilo allegedly fled the home prior to officers arrival.
He returned to the home at 6 a.m. and was arrested before being transported to Maricopa County Fourth Avenue Jail.
Gentilo, 41, faces first-degree murder charges.