When Dr. Jay Chapman invented the three-drug method of lethal injection used in most states, it was supposed to be, he said, a more humane type of execution.
But, 30 years later, Chapman now says the three-drug cocktail, which an apparently divided Supreme Court considered on Monday, hasn't always worked out as planned.
In a few highly publicized executions, it appeared that inmates were not properly anaesthetized before the drugs stopped their hearts -- possibly leading to excruciating pain before they died.
"The way in which the drugs are administered has not been carried out as it should be," Chapman, known as the "father of lethal injection," told ABC News.
The Supreme Court case, which comes at a crucial time for capital punishment, has raised a difficult question: how much potential pain and suffering is acceptable when the state ends a person's life? There has been a de facto moratorium on most lethal injections since the court agreed to hear the case in September.
Two death row inmates in Kentucky have challenged the state's method of execution, now used in 35 of the 36 states that have the death penalty, saying the lethal drug cocktail can cause unconstitutionally cruel amounts of pain. The system uses three drugs that knock out, paralyze and then stop the heart of the condemned.
Though it is unclear what the court will do, several states have planned alternatives, including a move back to execution methods once condemned as barbaric.
Over the years, authorities have moved from hangings to firing squads to the electric chair to gas chambers to, most recently, lethal injections. Each change was supposed to be an improvement over the previous method, one that would make the process easier on the condemned inmate – and, perhaps more importantly in the eyes of legislators, on the public.
But, as states have tried to make executions as palatable as possible, some critics argue, they have landed on a method that may cause extreme pain to those condemned to die. Some medical experts, in fact, say the least cruel way to kill inmates may be by the very methods that have been rejected as too inhumane.
"One of the great ironies about capital punishment when you look at it historically is that when executions appear to be more humane, the application of the death penalty becomes less humane," said Dr. Jonathan Groner, the trauma medical director of Children's Hospital in Columbus, Ohio, who has testified as a death penalty expert.
Lawyers for the death row inmates advocate using a different type of lethal injection, an overdose of a single drug that should be painless, if unpleasant to watch. Some states have planned other alternatives: several states allow electrocutions, hangings and firing squads as alternatives to lethal injections, and more plan to institute those other methods if lethal injections are declared unconstitutional. The Supreme Court is not expected to declare lethal injections as a whole unconstitutional, but could strike down the current method of injections.
"That's the whole point with lethal injection – you have this veneer of medical respectability," Groner said. "Probably the most painless execution method is the guillotine…So why don't we do that? Because it's not very pleasant, it's not aesthetically pleasing….We feel it's okay to kill people as long as it doesn't look too ugly."