For the first time in more than a century, Supreme Court justices are battling over state execution methods. Monday, the Court heard arguments from the state of Kentucky, which uses a three-drug cocktail in executions. That mixture is used to knock out, paralyze and then kill the prisoner. While some judges suggested they would uphold Kentuckys method of execution, several remained cautious. Opponents argue that if the initial anesthetic doesnt take hold, the third drug that stops the heart can cause excruciating pain. The second drug, meanwhile, paralyzes the prisoner so they cant let anyone know. Recent executions in Florida and Ohio took much longer than usual, with strong indications that prisoners suffered during the process. For now, executions in the U.S. have been halted while the Supreme Court explores the issue.