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.
What makes this approach different than prior death-case appeals is that it does not directly challenge the conviction or death sentence. Instead, lawyers for death-row inmates are focusing on the way those death sentences would probably be carried out. They argue that the three-drug protocol used in most of the 37 states that rely on lethal injection may not be as reliable as many Americans assume.
The three-drug protocol includes an initial painkiller, a chemical to induce total paralysis, and a final agent to immediately stop the heart.
Some experts say if the initial painkiller is incorrectly administered or wears off too soon, it can subject the condemned inmate to a horrible death. They say the second drug administered is designed to completely immobilize the inmate moments before the third drug is introduced to stop the heart.
At the center of most of these legal challenges is a scenario with all the horror of an episode of "Twilight Zone." It is described in a friend-of-the-court brief submitted in the Hill case at the Supreme Court by the group Physicians for Human Rights.
"If administered improperly, this combination of chemicals would cause an inmate to suffocate, while consciously experiencing the blinding pain of an injection of potassium chloride and a coronary arrest, while onlookers believe him to be unconscious and insensitive to any pain," says the brief.
It continues: "Yet all across the country, state lethal injection protocols fail to provide execution personnel the adequate training, appropriate procedures, and proper equipment necessary to administer lethal injection."
Although the Constitution does not require that state-sanctioned executions be painless, a lethal-injection execution botched in this way would qualify as cruel and unusual punishment, these lawyers say.
But the problem is, if the inmate is paralyzed and then dies, the necessary evidence to argue and win that case may well have died with the condemned prisoner, they add.
"Anyone who puts down an animal knows that there are other methods that are peaceful," says Bradley MacLean, a Nashville lawyer representing Mr. Abdur'Rahman.
Mr. MacLean says that the paralyzing agent used in the three-drug protocol, a chemical called Pavulon, is banned by 30 states - including Tennessee - for use in euthanasia of animals.
He says he is puzzled by the reluctance of state officials to address these concerns. He says unlike challenges to an inmate's death sentence, legal action seeking a change of procedure in carrying out a death sentence could ironically speed a client's execution rather than delay it.
But MacLean says states have so far resisted efforts to reform and modernize the lethal injection process.
"When we first brought our lethal injection action in 2002, most people who looked at what we were doing said there is no sense to bring this suit because they can change the protocols and eliminate all these problems in a matter of weeks," MacLean says. "We are now four years later and they haven't done a thing."
At least eight inmates have received stays of execution pending further litigation on the lethal injection issue, according to a report issued on Monday by Human Rights Watch. But the report adds that 10 other inmates have been denied stays and executed by lethal injection despite their concerns about the process.
That number rose to 11 last Friday after federal judges authorized the execution of Willie Brown in North Carolina. His execution had been temporarily delayed to investigate concerns that trained individuals should be present to monitor Mr. Brown's level of consciousness during the injection procedure.
According to a press report, the state agreed to have both a doctor and nurse use a "bispectral index monitor" to track Mr. Brown's brain activity and level of consciousness to ensure the execution wasn't unnecessarily painful.