The plaintiffs in the latest Supreme Court case, convicted murderers Ralph Baze and Thomas Bowling, say Kentucky's method of lethal injection creates an unnecessary risk of "terrifying conscious paralysis and suffocation" followed by "excruciatingly burning pain."
Kentucky, like most states, kills inmates using the three-drug protocol: sodium thiopental, an anesthetic that knocks out the inmate; pancurium bromide, which paralyzes the body; and potassium chloride, which stops the heart. The second drug, while medically unnecessary, stops the inmate from convulsing or making noise.
That combination, even critics acknowledge, can be painless. And lawyers for the state say safeguards are in place to make sure the drugs are administered properly. Kentucky has executed one prisoner by lethal injection, apparently without any problems.
But, critics argue, the drugs must be administered by people with proper training, which prison guards don't always have. If the anesthetic is not given correctly, the result could be a quietly agonizing death masked by the paralysis.
That appears to have happened in several widely reported cases. In Ohio, a condemned man raised his head midway through his execution to announce, "It's not working." In Florida, an execution took nearly half an hour and left the prisoner with chemical burns on his arm. A lawsuit filed recently by a prison guard in South Carolina described a "horrible death scene where the lethal syringe came out of the inmate's arm during execution."
"I think it is just ridiculous really that people would attempt to do this sort of thing without being properly trained," Chapman said.
Lawyers for the inmates advocate using the same method used to euthanize animals, an overdose of a barbiturate. That drug would be less painful, but probably slower and more unpleasant to watch. Groner said that the drug would cause a person to slowly turn blue and convulse as parts of their brain die. As an alternative, the inmates are asking for better monitoring of the three-drug process to ensure that the anesthetic is given properly
"The purpose of the second drug is appearances, really," said Richard Dieter, the director of the Center for Death Penalty Information. "It's not an anesthetic and it's not what kills you. It's about less twitching and shouting. That's where the state gets itself into some trouble – where it made paramount things that are just for appearances."
The Supreme Court has never declared a method of execution unconstitutional, though in oral arguments on Monday, several justices appeared troubled by the current method of lethal injections.
But conservative justices, including Antonin Scalia, said states should not be barred from executing prisoners even if officials sometimes make mistakes in administering the drugs, since states have adopted procedures designed to avoid inflicting pain.
"There is no painless requirement" in the Constitution, Scalia said.
"We have approved electrocution, we have approved death by firing squad," he said, according to a transcript of the argument. "I expect both of those have more possibilities of painful death than the protocol here."
And Chapman, for one, is not particularly sympathetic to the inmates.
"I think that execution by the method we've set up is far too humane for many of these people," he said. "Because of the things I've seen they've done to their victims."