INDIANAPOLIS (AP) — A federal death row inmate who befriended Timothy McVeigh attempted suicide the night before the Oklahoma City bomber was executed, the inmate's attorney said Monday.

David Hammer, who is diabetic, tried to kill himself by injecting insulin directly into one of his veins, but the attempt was detected and he was treated, said attorney Ronald Travis.

Officials at the U.S. Penitentiary in Terre Haute, where McVeigh was executed on June 11, would not confirm or deny the report, citing privacy concerns.

Travis said he had gotten no warning that his client was considering hurting himself. "I know he was deeply troubled by it (execution). I know that he and Mr. McVeigh apparently had become very close," Travis said.

In a daily journal published on a death row inmates' Internet site, Hammer wrote that he made the suicide attempt the night of June 10. McVeigh was put to death by injection at 7 a.m. the next day.

"I keep wondering how long until my own date with the executioner will arrive," Hammer wrote. "I wish I were dead right now, but I'm not. Death would be a welcome relief."

Hammer was sentenced to death for strangling his cellmate at the federal prison at Allenwood, Pa. Before that, he had faced a total of 1,200 years for crimes that included attempted murder and kidnapping.

Hammer has said that he and McVeigh met when they were being flown to the prison at Terre Haute, and they later had adjacent cells.