Great Bend ? Authorities will seek the death penalty for a man charged with murder in the killings of a Great Bend couple.

Sidney J. Gleason, 24, of Lyons, is charged with capital murder and first-degree murder in the shooting deaths of Darren R. Wornkey, 24, and Mikiala “Miki” Martinez, 19, on Feb. 21.

During a preliminary hearing Wednesday, Gleason pleaded not guilty to the murder charges and to charges of aggravated kidnapping, attempted murder, aggravated robbery and criminal possession of a firearm.

After Gleason’s plea, the Kansas Attorney General’s Office filed notice that it would seek the death penalty.

Gleason’s cousin, Damian Thompson, 25, previously pleaded guilty to first-degree murder in Martinez’s death. Authorities dropped capital murder charges against him in exchange for his testimony in Gleason’s trial.

In testimony Wednesday, Thompson said that he, Gleason and two others feared that Martinez might give police information about the stabbing and robbery of a 76-year-old man they were involved in on Feb. 12.

Thompson said they drove to Martinez’s house to intimidate her and found her and Wornkey in a vehicle.

Gleason ran to the vehicle carrying a handgun, Thompson said.

“I heard gunshots,” Thompson said. “Three, maybe four.”

Gleason told Martinez to get into the car, and Thompson said he drove to a rural location in northeast Barton County where he struck Martinez in the face with a gun and attempted to strangle her before shooting her in the chest.

“I told him we were even, and we got in the car,” Thompson testified.

Thompson said they left the body in a ditch and returned the next day to move the body to a heavily wooded ravine.

Thompson is expected to be sentenced Thursday to life in prison without the possibility for parole for 25 years.