Oklahoma City — Oklahoma plans to execute a man Thursday who was convicted of kidnapping, raping and killing a 7-year-old girl in 1984.

Richard Rojem, 66, has exhausted his appeals and is scheduled to receive a three-drug lethal injection at the Oklahoma State Penitentiary in McAlester.

During a clemency hearing earlier this month, Rojem denied responsibility for killing his former stepdaughter, Layla Cummings. The child's mutilated and partially clothed body was discovered in a field in western Oklahoma near the town of Burns Flat. She had been stabbed to death.

"I wasn't a good human being for the first part of my life, and I don't deny that," said Rojem, handcuffed and wearing a red prison uniform, when he appeared via a video link from prison before the state's Pardon and Parole Board. "But I went to prison. I learned my lesson and I left all that behind."

The board unanimously denied Rojem's bid for mercy. Rojem's attorney, Jack Fisher, said there are no pending appeals that would halt his execution.

Rojem was previously convicted of raping two teenage girls in Michigan and prosecutors allege he was angry at Layla Cummings because she reported that he sexually abused her, leading to his divorce from the girl's mother and his return to prison for violating his parole.

"For many years, the shock of losing her and the knowledge of the sheer terror, pain and suffering that she endured at the hands of this soulless monster was more than I could fathom how to survive day to day," Layla's mother, Mindy Lynn Cummings, wrote to the parole board.

Oklahoma Attorney General Gentner Drummond said Rojem is a "real-life monster who deserves the same absence of mercy he showed to the child he savagely murdered," CBS Oklahoma City affiliate KWTV reports.

Rojem's attorneys argued that DNA evidence taken from the girl's fingernails did not link him to the crime and urged the clemency board to recommend his life be spared and that his sentence be commuted to life in prison without parole.

"If my client's DNA is not present, he should not be convicted," Fisher said.

Prosecutors say plenty of evidence other than DNA was used to convict Rojem, including a fingerprint that was discovered outside the girl's apartment on a cup from a bar Rojem left just before the girl was kidnapped. A condom wrapper found near the girl's body also was linked to a used condom found in Rojem's bedroom, prosecutors said.

A Washita County jury convicted Rojem in 1985 after just 45 minutes of deliberations. His previous death sentences were twice overturned by appellate courts because of trial errors. A Custer County jury ultimately handed him his third death sentence in 2007.

Oklahoma, which has executed more inmates per capita than any other state in the nation since the death penalty was reinstated in 1976, has carried out 12 executions since resuming lethal injections in October 2021 following a nearly six-year hiatus resulting from problems with executions in 2014 and 2015.

Death penalty opponents planned to hold vigils Thursday outside the governor's mansion in Oklahoma City and the Oklahoma State Penitentiary in McAlester.