OKLAHOMA CITY (AP) - A 27-year-old man charged with fatally stabbing his father - who was Oklahoma's labor commissioner - is due in court.

A preliminary hearing is scheduled Friday for Christian Costello, who is charged with first-degree murder in the Aug. 23 stabbing death of Mark Costello. Prosecutors will present evidence before Special Judge Lisa Hammond and Hammond will decide whether a crime has been committed and whether there is probable cause that Christian Costello committed it.

Prosecutors say Costello attacked his father with a knife and repeatedly stabbed him at an Oklahoma City restaurant. Costello has pleaded not guilty to first-degree murder.

Costello's attorney, Chief Public Defender Bob Ravitz, has said Costello is "very remorseful." Costello's family has said in a statement that he suffers from a mental illness.