GLENDALE, Ariz. (AP) — A Glendale man accused of fatally beating his wheelchair-bound stepfather earlier this month has pleaded not guilty in the case.

Maricopa County Superior Court officials say 46-year-old Heath McConkey entered his plea Thursday. His initial pretrial conference is scheduled for Sept. 11.

McConkey was arrested July 7 on suspicion of first-degree murder.

Court records show that McConkey's 72-year-old stepdad was a disabled veteran.

Glendale police were called to the home by McConkey's mother. She called 911 after finding the two men on the floor in a pool of blood.

Police say McConkey was mad at his stepfather, pulled him out of bed and punched and kicked him until passing out.

McConkey's mother told police her son has been diagnosed with depression and anxiety, but refuses to take his daily medication.