The 10th U.S. Circuit Court of Appeals on Monday further delayed convicted murderer Mark Hopkinson's death sentence pending a review of grand jury transcripts by the U.S. District Court in Cheyenne, Wyo.

Hopkinson, who has been on death row since 1979, had challenged four first-degree murder convictions stemming from the bombing deaths of three members of the Vincent Vehar family in Evanston, Wyo., in 1977, and the killing of Jeffrey Green, which occurred more than a decade ago.The Fort Bridger, Wyo., man was convicted in 1979 of the for-hire slaying of Green, who was killed while Hopkinson was in a light-security federal penitentiary in Lompoc, Calif. Hopkinson has denied any connection to the slaying. The death penalty was imposed for Green's murder.

Green had been scheduled to give testimony before a federal grand jury about the 1977 bombing when he was killed by Michael Hickey.

Also in 1977, Hopkinson hired Green to plant a bomb on the car of George Mariscal, a Phoenix, Ariz., attorney who allegedly owed Hopkinson money. But Green was stopped for speeding in Coalville, Utah, and the bomb was discovered. Green was arrested and jailed.

Green testified later that Hopkinson had hired him to bomb Mariscal's car. He also testified that when he heard about the Vehar murders, "I had thought that Mark (Hopkinson) had the job done and I believed that he was responsible for it, but I never did know for sure."

Hopkinson reportedly threatened Green with death following the testimony.

State prosecutors portrayed the torture slaying of Green as the "aggravating circumstances" that they said justified the death sentence for Hopkinson.

In 1979, Hopkinson also was convicted of the bombing deaths of Vincent Vehar, his wife and a son.