Oklahoma Labor Commissioner Mark Costello was fatally stabbed at a restaurant Sunday night by his son, police said.
Mark Costello was at a Braum’s restaurant when he was stabbed in the head and neck, police told CNN. He died at a local hospital.
Costello’s 26-year-old son, Christian Costello, was arrested in the parking lot.
Authorities didn’t release a motive.
Police told CNN affiliate KFOR that the attack started inside the restaurant and then continued outside.
Witness Patrick Spencer was driving nearby when he saw a wounded man outside the restaurant. He thought the man had been shot.
“We got a closer look and there was a guy chasing him with a knife,” Spencer told KFOR. “It was shocking and dramatic.”
He told the affiliate that the two men circled the building a few times before he attacker stabbed Costello in the head.
“He was pretty bloody, and the wife was trying to get him in their vehicle to get him away from the suspect,” Spencer told the affiliate.
He said the attack finally ended when a witness in the parking lot used his vehicle to ram the assailant to the ground.
Mark Costello became Oklahoma’s labor commissioner in 2010. Before that, he founded the telephone software company AMCAT, according to his official website.
He sold AMCAT in 2007 and founded several other technology companies.
Sen. James Lankford, a fellow Republican from Oklahoma, mourned the loss of Costello on Twitter.
“My family is stunned & deeply grieved to hear of the tragic death of Labor Commissioner Mark Costello,” he tweeted. “What a tragedy.”
Costello was married and had five children.