In a twist, lawyers argue that the method of execution - not the death penalty itself - is cruel if administered improperly.
As the primary form of capital punishment in America, lethal injection is largely viewed as the most humane method yet developed of state-sanctioned execution.
It is quick and relatively cheap. Few inmates would prefer to face an alternative, such as the gas chamber or the electric chair. The condemned inmate is widely believed to feel no pain.
But such assumptions are increasingly coming under attack. And, perhaps more important, judges appear to be taking notice. A US district judge in California has scheduled a full evidentiary hearing next week in the case of convicted murderer Michael Morales to investigate the protocol used for lethal injection in that state. And lawyers in Tennessee are asking the US Supreme Court to take up the case of Abu-Ali Abdur'Rahman, which challenges the lethal-injection protocols in their state.
In addition, Wednesday the US Supreme Court takes up a Florida case that could make it easier for death-row inmates to launch last-minute challenges to the methods used to carry out executions by lethal injection. In that case, Hill v. McDonough, death-row inmate Clarence Hill filed a last-minute appeal challenging Florida's lethal injection protocol.
At issue in the case is whether the appeal should be barred (because of laws passed by Congress restricting last-minute death-penalty appeals), or whether it should be permitted (under a different law that allows inmates to file civil-rights actions challenging the conditions of their confinement and treatment in prison).
If the high court permits Mr. Hill's 11th-hour suit to go forward, it will open courthouse doors across the country to what has become the hottest trend in death-row litigation: legal challenges to lethal injection.