Johnnie Baston is scheduled to die March 10 for the slaying of Chong-Hoon Mah, 53, a South Korean immigrant who operated two retail stores in Toledo.
Baston asked for mercy on the grounds that Mah's family opposes the death penalty and also based on Baston's chaotic upbringing.
The nine-member parole board said the severity of Mah's execution-style killing and Baston's failure to accept responsibility for it outweigh the personal beliefs of Mah's family about capital punishment.
The board also said Baston continues to suggest he may have been involved in the crime but didn't kill Mah despite overwhelming evidence to the contrary. Baston's attorneys aren't challenging his conviction.
"There was nothing presented at the clemency hearing to suggest any manifest injustice in the verdict and sentence imposed," the board said in its decision. A message left with Baston's public defender seeking comment on Friday wasn't immediately returned.
The Mah family is opposed to the death penalty and believes the ultimate punishment is not something for people to decide - only God. The family is satisfied with Baston serving a prison sentence.
"It's never going to repair anything that's already been done," Mah's son, Peter Mah, told The Associated Press in a phone interview Wednesday, before the board's decision.
"It's not going to make me feel better to see Johnnie Baston die. It's not going to bring back my dad. It's not going to do any of these things," Mah said.
Mah, acting as family spokesman, signed an affidavit last month that outlines the family's opposition to the death penalty. The family has held that position since Baston's trial.
Mah, 38, a Chicago restaurant owner, said the family is satisfied with Baston serving time.
Opposition by some victims' family members to an execution is not uncommon. It's rarer for a family to stand unified against the death sentence.
In 2009, then-Ohio Gov. Ted Strickland spared Jeffrey Hill, sentenced to die for killing his mother in a crack-cocaine induced robbery, based on the opposition of surviving family members to an execution. But in that case, the victim's relatives were also Hill's relatives.
Chong-Hooh Mah was a journalist in South Korea before emigrating and opening two retail stores in Toledo, including Continental Wigs and Things in downtown Toledo. He started life over as a manual laborer before opening his stores and rarely took a day off, his brother, Chonggi Mah, testified at the end of Baston's 1995 trial.
Mah's wife, Jin Ju Mah, found her husband dead in the back of the store after she grew worried because she couldn't reach him on the phone.
Prosecutors acknowledge the family's opposition to Baston's execution but point out the family testified strongly about its anguish and Baston's lack of remorse.
"Most painful of all was watching the convict sit through the trial with a blank expression," Chonggi Mah told the three-judge panel that sentenced Baston.
"Not once through the whole thing did he show that he was sorry or show any sadness about what he did to my brother and his family," he said.
Peter Mah, then an Ohio State University student, also expressed deep sorrow during his testimony to the three-judge panel.
"When my father died last March part of every one of my family died with him," Mah said in 1995. "Laughter and joy that used to surround our house was gone. All the dreams that we had for the future were taken away."
Baston's attorneys say he was abandoned as an infant, has never seen his mother and was rebuffed by his father when he attempted to move back in with him. As a boy, Baston would wander the streets with his dog trying to find his mother.
Also on Friday, Gov. John Kasich rejected clemency for an Ohio inmate with Nazi sympathies who has spent 27 years on death row for killing three men at Cleveland State University.
Frank Spisak is scheduled to die Feb. 17. He has blamed the 1982 murders on his hatred of gays, blacks and Jews and also claimed his crimes were sparked by mental illness related to confusion about his sexual identity.
Spisak's attorney, Mike Benza, called the decision disappointing.
"The failure of leadership to move the State of Ohio past the point where it is acceptable to execute the severely mentally ill is another opportunity lost," he said.