A Cahokia man pleaded guilty Friday in the murder of a Centreville police officer.

Lemuel A. Houston, 25, pleaded guilty but mentally ill in a St. Clair County courtroom to the shooting death of Centreville Police Lt. Greg Jonas, 59. Jonas was shot once in the back of the head in 2009.

Sentencing was scheduled for Aug. 30 in front of St. Clair County Chief Circuit Judge John Baricevic, according to St. Clair County State's Attorney Brendan F. Kelly.

The state intends to seek a natural life sentence without the possibility of parole for Houston, Kelly said at the hearing.

A plea of "guilty but mentally ill" means that at the time of the commission of the criminal offense a defendant was suffering from a mental illness, but the defendant was not insane and is not relieved of criminal responsibility for his conduct.

Jonas was shot just before 2 a.m. June 2, 2009, at the Ernest Smith Apartments at 47th Street and Piggot Avenue in Centreville. He was found lying in the street near his police cruiser.

The Major Case Squad of Greater St. Louis was tapped to work the case and 30 to 35 officers investigated. Houston was picked up a day after the shooting; by the next day, he was charged.

Houston, who was 22 at the time of the shooting, told police he did not want to get booked on a gun charge when Jonas stopped him. Jonas was on duty patrolling the neighborhood, when he got out of his vehicle to talk to Houston and others with him. Houston shot Jonas and ran.

Contact reporter Jennifer A. Bowen at jbowen@bnd.com or 239-2667.