Only hours before his execution, convicted killer Robert Brecheen was found in his holding cell, groggy and breathing heavily from an overdose of sedatives.

Doctors rushed him to a hospital and worked feverishly to pump his stomach and declare him mentally fit before the state executed him by injection early Friday."Certainly, there's irony," said Larry Field, director of Oklahoma's corrections department. "But we're bound by the law, the same law that he violated."

Brecheen, condemned for the 1983 shooting death of Marie Stubbs, whose husband had refused him a $400 loan, looked tired and pale as he was led to the death chamber two hours late for the midnight execution.

Before three drugs were pumped into his arm, Brecheen, 40, made a brief final statement, but it wasn't audible because of problems with a microphone. Guards later said he thanked his parents and made no mention of the overdose.

State police began an investigation into how Brecheen obtained the sedatives.

He had been strip-searched when he was placed in the holding cell next to the execution chamber Thursday morning, and his belongings were searched. Later, he declined a special last meal and passed up the stew-and-noodle dinner served to other inmates.

He appeared to be asleep in his holding cell at 7:43 p.m., only minutes after meeting with his attorneys, said corrections spokesman Jerry Massie.

Prison staff tried unsuccessfully to awaken him at 9 p.m.

The overdose was not life-threatening, said Assistant Attorney General Diane Blalock.