The Latest on Oklahoma stabbing: Police say motive unknown

Before you go, we thought you'd like these...
Before you go close icon
Oklahoma Politician Stabbed To Death, Son Being Held

OKLAHOMA CITY (AP) — The latest on the fatal stabbing of Oklahoma's labor commissioner (all times local):

___

9:55 a.m.

Police say the 26-year-old man accused of fatally stabbing his father, an Oklahoma politician, brought a knife to the restaurant where they'd arranged to meet.

Oklahoma City Capt. Paco Balderrama said Monday that investigators don't know yet why Christian Costello stabbed his father, Labor Commissioner Mark Costello, at the restaurant Sunday evening.

See photos of Mark Costello and the crime scene:

15 PHOTOS
Oklahoma politician Mark Costello stabbed
See Gallery
The Latest on Oklahoma stabbing: Police say motive unknown
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)
Oklahoma Labor Commissioner Mark Costello gestures as he speaks during a news conference at the state fairgrounds in Oklahoma City, Wednesday, Sept. 10, 2014. The Oklahoma State Fair begins Sept. 11. Department of Labor ride inspectors will be on the ground at the Oklahoma State Fair for the duration of the fair. (AP Photo/Sue Ogrocki)
This undated photo provided by the Oklahoma County Sheriff's Office shows Christian Costello. Costello is accused of having stabbed his father, Oklahoma's labor commissioner Mark Costello to death Sunday evening, Aug. 23, 2015, at a fast-food restaurant in Oklahoma City. (Oklahoma County Sheriff's Office via AP)
Christian Costello, son of Oklahoma Labor Commissioner Mark Costello, is placed in a police car, 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) 
Police investigate the scene where Oklahoma Labor Commissioner Mark Costello was fatally stabbed, Sunday, Aug. 23, 2015, in Oklahoma City. Christian Costello, son of Mark Costello, was arrested on a first-degree murder complaint, police said. (Nate Billings/The Oklahoman via AP) 
Police investigate the scene where Oklahoma Labor Commissioner Mark Costello was fatally stabbed, Sunday, Aug. 23, 2015, in Oklahoma City. Christian Costello, son of Mark Costello, was arrested on a first-degree murder complaint, police said. (Nate Billings/The Oklahoman via AP)
Labor Commissioner Mark Costello gestures as he answers a question at a news conference in Oklahoma City, Tuesday, March 26, 2013. Costello said that the Oklahoma Department of Labor is shutting down its satellite office in Tulsa due to federal budget cuts and offering the office’s 11 full-time employees voluntary buyouts or jobs in the agency’s Oklahoma City office. (AP Photo/Sue Ogrocki)
Republican Mark Costello gestures as he speaks to a Republican Party victory party in Oklahoma City, Tuesday, Nov. 2, 2010. Costello defeated Democratic incumbent Lloyd Fields to become Oklahoma's next Labor Commissioner. (AP Photo/Sue Ogrocki)
Oklahoma Labor Commissioner Mark Costello gestures as he speaks during a news conference at the state fairgrounds in Oklahoma City, Wednesday, Sept. 10, 2014. The Oklahoma State Fair begins Sept. 11. Department of Labor ride inspectors will be on the ground at the Oklahoma State Fair for the duration of the fair. (AP Photo/Sue Ogrocki)
JUST IN: Sen. @jameslankford responds to the stabbing death of #OK Labor Commissioner Mark Costello. @NEWS9 http://t.co/P4LGWV5naL
Mark Costello was one of the most honest and decent political leaders I've ever dealt with. I am so saddened by his death
My family is stunned & deeply grieved to hear of the tragic death of Labor Commissioner Mark Costello. What a tragedy.
Folks, don't wait for the Governor's order. Please lower your Oklahoma flags to half-staff now, in honor of Commissioner Mark Costello.
Unbelievable news about Labor Commissioner Mark Costello. Condolences to his family on this unbelievable and unexpected loss.
of
SEE ALL
BACK TO SLIDE
SHOW CAPTION +
HIDE CAPTION

Balderrama says police interviewed 17 witnesses, including the victim's wife and suspect's mother, Cathy Costello, who was in a vehicle outside the restaurant.

He says he thinks Cathy Costello tried to stop her son from attacking her husband.

SEE ALSO: Police: Son arrested after Oklahoma official fatally stabbed

9:20 a.m.

Police records show that a man detained after the stabbing death of his father, Oklahoma's labor commissioner, was once held for three months for treatment of mental illness.

Records obtained by The Associated Press on Monday show that Christian Costello received a deferred sentence for driving under the influence of drugs in 2012. In his plea agreement, he disclosed the mental treatment and said he was taking mood stabilizers.

Costello is being held on a first-degree murder complaint after the stabbing death of his father, Oklahoma Labor Commissioner Mark Costello, on Sunday.

Last October, the younger Costello was accused of outraging public decency. Police say he exposed himself at a Catholic elementary school.

More on AOL.com:
Police: Louisiana trooper dies after being shot in head
Peyton Manning has no feeling in his fingertips
Hometown, church mobilize to support Plains' Jimmy Carter

Read Full Story

Sign up for Breaking News by AOL to get the latest breaking news alerts and updates delivered straight to your inbox.

Subscribe to our other newsletters

Emails may offer personalized content or ads. Learn more. You may unsubscribe any time.

From Our Partners