Oklahoma City police take photos of Christian Costello, son of Oklahoma Labor Commissioner Mark Costello, before placing him in a police vehicle, Sunday, Aug. 23, 2015, at the scene where Mark Costello was fatally stabbed in Oklahoma City. Christian Costello was arrested on a first-degree murder complaint, police said. (Nate Billings/The Oklahoman via AP) LOCAL STATIONS OUT (KFOR, KOCO, KWTV, KOKH, KAUT OUT); LOCAL WEBSITES OUT; LOCAL PRINT OUT (EDMOND SUN OUT, OKLAHOMA GAZETTE OUT) TABLOIDS OUT; MANDATORY CREDIT
Nate Billings—The Oklahoman/AP
Police arresting Christian Costello, son of Oklahoma Labor Commissioner Mark Costello, on a first-degree murder complaint for fatally stabbing his father at a restaurant in Oklahoma City, on Aug. 23, 2015.

Mark Costello’s 26-year-old son was arrested