FILE – This undated file photo provided by the Ohio Department of Rehabilitation and Correction shows death row inmate Alva Campbell, convicted of fatally shooting Charles Dials, during a carjacking in 1997. Officials say Campbell, a twice convicted Ohio murderer whose execution was halted in November 2017 when a vein couldn’t be found to administer execution drugs has died of natural causes. A spokeswoman for the Ohio Department of Rehabilitation and Correction says Campbell was found unresponsive Saturday, March 3, 2018 in his cell at a prison in Chillicothe and was pronounced dead at a hospital just before 5:30 a.m. (Ohio Department of Rehabilitation and Correction via AP, File)

CLEVELAND - A twice-convicted murderer whose execution in November had to be halted when a usable vein couldn't be found to administer execution drugs died Saturday morning of natural causes, a spokeswoman for the Ohio Department of Rehabilitation and Correction said.

Alva Campbell, 69, was found unresponsive in his death row cell Saturday morning at a prison in Chillicothe and was pronounced dead shortly before 5:30 a.m. at a hospital, prison department spokeswoman JoEllen Smith said.

The U.S. 6th Circuit Court of Appeals last month denied a challenge filed by Campbell and another death row inmate to Ohio's execution protocol, arguing the three-drug combination used to carry out the death penalty posed an unacceptable risk of pain and suffering.

After the failed execution attempt in November, Ohio Gov. John Kasich set a new execution date of June 5, 2019, for Campbell.

Campbell was sentenced to die in 1998 in Franklin County, which includes Ohio's capital city of Columbus, after being convicted of killing an 18-year-old man during a carjacking.

Campbell was in a wheelchair in 1997 when he overpowered a sheriff's deputy on the way to a Franklin County court hearing on armed robbery charges. He took the deputy's gun, carjacked Charles Dials and drove around with him for several hours before shooting him twice in the head.

He spent 20 years in prison after being convicted in the 1972 slaying of a man at a bar in Cleveland.

Franklin County Prosecutor Ron O'Brien had previously referred to Campbell as "the poster child for the death penalty."

Responding to the news of Campbell's death, O'Brien said on Twitter: "Due to 20 years of frivolous post-conviction litigation, he successfully ran the clock out on justice due to the state and the victim's family."

Campbell's attorney, David Stebbins, told The Associated Press that Campbell had "suffered from a lot of pretty serious diseases for long time." He said he last visited with Campbell about a week ago.

"It was only a matter of time before this caught up with him," Stebbins said. "In some ways, it was a relief."

Stebbins said an autopsy will be performed on Monday.

News from © The Associated Press, 2018