A landmark scientific study has raised new doubts about the lethal injections used on death row prisoners. Researchers say the drug cocktail used for executions is unreliable and could render prisoners paralyzed but not unconscious. Prisoners are then subjected to extreme pain while being unable to cry out. Leonidas Koniaris, a University of Miami surgery professor who led the study, said, “This raises the possibility people are being tortured and you can’t see it because they are paralyzed. I’m not sure a civilized society should be doing this.”