OKLAHOMA CITY (AP) — The deadly stabbing of a prominent Oklahoma politician by his son was a premeditated attack in which the suspect intentionally separated his father and mother before the assault, an Oklahoma City detective wrote in an affidavit filed Wednesday.
In a request to search the condominium where Christian Costello lived, police Inspector Cris Cunningham wrote that investigators believe Sunday night's stabbing of Oklahoma Labor Commissioner Mark Costello was planned in advance.
"The suspect brought the above listed knife with him to the location," Cunningham wrote. "The suspect also requested to speak with the victim alone, thus separating him from another family member who was present at the location."
Police have said Christian Costello, 26, pulled out a knife while he and his 59-year-old father talked at a Braum's fast-food restaurant on Oklahoma City's northwest side. The attack continued after Mark Costello ran into the parking lot, where his wife, Cathy Costello, tried to intervene and stop the assault, police said.
The state medical examiner's office on Tuesday ruled that Mark Costello died from stab wounds to the neck and classified the death as a homicide.
Christian Costello is being held on a preliminary charge of first-degree murder. Jail and court records do not indicate if he has retained an attorney.
Police on Tuesday searched his condo, located a few blocks from where the attack took place. Court records indicate investigators were looking for evidence including any edged weapons, computer equipment, letters or correspondence, but they took no items.
Christian Costello once served 90 days in a mental health facility and took mood stabilizers, according to court records. His family said in a statement he suffers from a mental illness, although they did not specify which one.
Mark Costello's body will lie in repose on Thursday in the second-floor Capitol rotunda, and a candlelight vigil will be held Thursday night on the south steps of the Capitol.
A funeral Mass will be held Saturday at the St. Monica Catholic Church in Edmond.
Follow Sean Murphy at www.twitter.com/apseanmurphy .