Kasich said in a statement posted on his website that Ronald Post, convicted of fatally shooting Helen Vantz, 53, during a 1983 robbery at the Slumber Inn in Elyria, instead should spend the rest of his life in prison.
"Regardless of the heinous nature of their crime, a criminal defendant is entitled to an effective defense, especially in a death penalty case," Kasich wrote. "The Parole Board's conclusion is that Ronald Post did not come close to receiving such a defense. After my own careful review, I agree.
"Therefore I am ordering that he spend the rest of his life in prison with no possibility of ever getting out. This decision should not be viewed by anyone as diminishing this awful crime or the pain it has caused."
A federal judge last month rejected Post's argument that his obesity made his veins unsuitable for Ohio's lethal injection procedure, and therefore amounted to cruel and unusual punishment.
Post weighted between 400 and 500 pounds this fall.
The Parole Board voted 5-3 Friday to recommend Post not be executed, citing mistakes his original attorneys made, including having Post take a polygraph test administered an examiner who had already been retained by prosecutors and having Post enter a no contest plea with no assurance it would be considered mitigation in the sentencing phase, The (Cleveland) Plain Dealer reported.