A 66-year-old Arizona death row inmate was put to death Wednesday by lethal injection at the state prison in Florence.

Arizona Attorney General Mark Brnovich said in a statement that Frank Atwood was killed for his murder conviction in the killing of 8-year-old Vicki Lynne Hoskinson, whose body was found in a desert, reported ABC News. Before Hoskinson was killed, she went missing. She disappeared after she left her home in Tucson to drop a birthday card in a nearby mailbox.

After rejecting a final appeal by Atwood’s lawyers, the U.S. Supreme Court cleared the way for his execution Wednesday morning. Brnovich said that the inmate, who was the second Arizona prisoner to be put to death in less than a month, died at 10.16 a.m. This comes after the execution of Clarence Dixon last month.

Witnesses to the execution said that Atwood, who had claimed innocence, was accompanied through the process of being prepared for the lethal injection by a priest. He did not address the 1984 killing with his last words. He reportedly thanked the priest “for coming today and shepherding me into the faith.” He added that he prayed the "Lord will have mercy on all of us and that the Lord will have mercy on me.”

The late girl's mother, Debbie Carlson, was also a witness to the execution. After Atwood died, she said, “Vicki was a vibrant little girl with an infectious laugh and a smile that would melt your heart." She added that her daughter's "royal blue eyes reflected an old soul of wisdom."

In recent weeks, judges had rebuffed attempts by Atwood's lawyers to have the execution delayed. In court filings, his lawyers told the Supreme Court that the aggravating factor that made his crime eligible for the death penalty was applied invalidly. In 1975 in California, Atwood was convicted for lewd and lascivious conduct with a child under 14. Then in 1987, he was convicted of Hoskinson's murder. In the past, judges rejected that legal argument. The lawyers also said that their client would undergo excruciating suffering strapped to the gurney while lying on his back. The inmate had a degenerative spinal condition.

According to CNN, Brnovich said in a statement that to an innocent child whose life was "brutally taken and a family that has had to endure decades of suffering, Arizonans will never forget."

Mirror reported that his last supper included jelly and peanut butter. He also had salami, mustard, wheat bread and tortilla chips. He washed it down with either water or a juice packet.

Representation image. Pixabay.