An Ohio judged ruled the state's method of putting prisoners to death was unconstitutional because two of three drugs used in the lethal injection process can cause extreme pain, the judge said.
Lorain County Common Pleas Judge James Burge said Tuesday the state's lethal injection procedure doesn't provide the quick and painless death required by Ohio law.
Burge said Ohio must stop allowing a combination of drugs and focus instead on a single, anesthetic drug.
An appeal to the Ohio Supreme Court was likely.
A splintered Supreme Court cleared the way in April for states to resume executions on hold for seven months.
Virginia had immediately lifted its moratorium, while Oklahoma officials said it would resume execution dates for murderers. Other states were to follow, while Ohio continued to weigh the legality of the drugs used in lethal injections.
The major criticism of the three-drug execution procedure in Ohio is that if the executioner administers too little anesthetic or makes mistakes in injecting it, the inmate could suffer excruciating pain from the other two drugs.
Ohio has executed 26 inmates since it resumed putting prisoners to death in 1999.