02/01/2014 07:51 GMT | Updated 23/01/2014 10:52 GMT

Gary Sherrill 'Killed Son David, 13 With Axe, Believing Him To Be A Flesh-Eating Demon'

Police say a 51-year-old man has confessed to killing his teenage son with an axe – because he apparently believed him to be a flesh-eating demon.

Gary Sherrill was arrested on suspicion of first-degree murder on New Year’s Eve, AP reports.

Sherrill, of Phoenix, Arizona, shared custody of 13-year-old David with his ex-wife.

She notified police when Sherrill failed to return the boy to her home on Tuesday.

Sergeant Steve Martos told KNXV Sherrill confessed to killing the boy with an axe and told officers he was afraid of his son, believing him to be a demon who wanted to eat him.

Neighbours told the channel Sherrill had been acting “strange” lately, with one adding: “He had been screaming at a tree the other day.”