Police: Son Planned Attack That Killed Mark Costello

Oklahoma City police said a man accused of stabbing and killing his father, Oklahoma Labor Commissioner Mark Costello, had planned the attack and brought the murder weapon with him before meeting with the victim.

A search warrant came back clean after authorities looked inside Christian Costello’s apartment. According to police, Costello lived in an apartment across the street from the Braum’s where he’s accused of stabbing and killing his father, Commissioner Costello.

8/24/2015 Related Story: Son Arrested For Murder In Death Of OK Labor Commissioner

According to court documents released on Wednesday, authorities found the knife Costello reportedly used to kill his father in the parking lot of the restaurant.

Through investigation, officers learned that Costello had planned the assault. He brought the knife with him to the location, and also requested to speak with Commissioner Costello alone, separating him from another family member who was present at the restaurant.