Daniel Bedford is scheduled for execution Tuesday for killing Gwen Toepfert, 25, and John Smith, 27, in 1984. He has been on death row longer than his ex-girlfriend was alive.
"Enough is enough is enough is enough," said Hamilton County Common Pleas Court Judge Norbert Nadel, The Cincinnati Enquirer reported.
Bedford's lawyers said he should not be put to death because he has dementia.
"He doesn't understand why the death penalty is being imposed on him," attorney Carol Wright said. "He's a low-functioning individual."
Ohio forbids execution of inmates legally deemed insane, she said.
Assistant Prosecutor Ron Springman said Bedford's testimony before the parole board that denied him clemency shows "he fully understands the nature of the death penalty and he fully understands why it was imposed on him."
Nadel denied Bedford's request to declare him insane or set a hearing on his civil case -- a first in Ohio by an inmate fighting execution.
Wright said she would appeal immediately.