Lethal-injection drugs are in short supply in the United States, and with lawyers questioning their effectiveness, some lawmakers in some death-penalty states are considering bringing back relics of a more gruesome past: firing squads, electrocutions and gas chambers.
Most states abandoned those execution methods more than a generation ago in a bid to make capital punishment more palatable to the public and to appease a judicial system worried about inflicting cruel and unusual punishments that violate the Constitution.
But to some elected officials, drug shortages and recent legal challenges are beginning to make lethal injection seem vulnerable to complications.
"This isn't an attempt to time-warp back into the 1850s or the wild, wild West or anything like that," said Rick Brattin, a Republican representative in the state of Missouri. This month he proposed making firing squads an execution option. "It's just that I foresee a problem, and I'm trying to come up with a solution that will be the most humane yet most economical for our state."
Like Brattin, a Wyoming lawmaker this month drafted a bill to allow firing squads. Missouri's attorney general and a state lawmaker have raised the notion of rebuilding the state's gas chamber. And a Virginia lawmaker wants to make electrocution an option if lethal-injection drugs are not available.
In recent years, European drug makers have stopped selling lethal-injection chemicals to prisons because they do not want their products used to kill. Earlier this month Hospira, the sole American manufacturer of an anaesthetic widely used in executions, said it would stop making the drug. It had planned production in Italy, but that country's authorities said they would bar its export if the drug, sodium thiopental, might be used for capital punishment.
At least two recent executions are also raising concerns about the drugs' effectiveness. Last week, Ohio inmate Dennis McGuire took 26 minutes to die by injection, gasping repeatedly as he lay on a gurney with his mouth opening and closing. On January 9, Oklahoma inmate Michael Lee Wilson's final words were, "I feel my whole body burning."
Brattin, the Missouri Republican, said questions about the injection drugs were sure to end up in court, delaying executions and forcing states to examine alternatives. It was not fair, he said, for relatives of murder victims to wait years, even decades, to see justice served while lawmakers and judges debate execution methods.
If adopted, such measures could return some executions to a more harrowing time when inmates were hanged, electrocuted or shot to death by marksmen.
States began employing lethal injections in the 1980s in the belief that powerful sedatives and heart-stopping drugs would end violent spectacles with more clinical deaths while limiting, if not eliminating, inmates' pain.
The total number of US executions has declined in recent years, from a peak of 98 in 1999 to 39 last year. Some states have overturned their death penalties. Many have cases tied up in courts. Those that persist with executions find them increasingly difficult to conduct because of the scarcity of drugs and doubts about how well those anesthetics work.
Missouri threw out its three-drug lethal injection procedure after it could no longer obtain the drugs. State officials altered its method in 2012 to use propofol, the same substance found in the system of pop star Michael Jackson after he died of an overdose in 2009.
The governor of the state of Missouri, Jay Nixon, stayed the execution of serial killer Joseph Paul Franklin in October and ordered the state's Department of Corrections to find a new drug.
Days later, the state announced it had switched to a form of pentobarbital. Like other states, Missouri has refused to divulge where the drug comes from or who makes it.
Missouri has carried out two executions using pentobarbital: Franklin in November and Allen Nicklasson in December. Neither inmate showed outward signs of suffering, but the secrecy of the process resulted in a lawsuit and a legislative inquiry.
Michael Campbell, assistant professor of criminal justice at the University of Missouri-St Louis, said some lawmakers simply did not believe convicted murderers deserved any mercy.
"Many of these politicians are trying to tap into a more populist theme that those who do terrible things deserve to have terrible things happen to them," Campbell said.
Richard Dieter, executive director of the Death Penalty Information Centre, an organisation that disseminates data about capital punishment, cautioned that the punishment proposals could create a backlash.
"These ideas would jeopardise the death penalty because, I think, the public reaction would be revulsion, at least from many quarters," Dieter said.
Some states already provide alternatives to lethal injection. Condemned prisoners may choose the electric chair in eight states: Alabama, Arkansas, Florida, Kentucky, Oklahoma, South Carolina, Tennessee and Virginia. An inmate named Robert Gleason was the most recent to die by electrocution, in Virginia in January 2013.
Arizona, Missouri and Wyoming allow for gas-chamber executions. Missouri no longer has a gas chamber, but attorney general Chris Koster, a Democrat, and Missouri state Senator Kurt Schaefer, a Republican, last year suggested rebuilding one. So far, there is no bill to do so.
Delaware, New Hampshire and Washington state still allow inmates to choose hanging. The last hanging in the US was Billy Bailey in Delaware in 1996. Two prisoners in Washington state have chosen to be hanged since the 1990s: Westley Allan Dodd in 1993 and Charles Rodman Campbell in 1994.
Since the end of the American civil war, there have been three civilian firing squad executions in the US, all in Utah. Gary Gilmore uttered his famous final words - "Let's do it" - on January 17, 1977, before his execution, which ended what amounted to a 10-year national moratorium on the death penalty. Convicted killers John Albert Taylor in 1996 and Ronnie Lee Gardner in 2010 were also put to death by firing squad.
Firing squads typically consist of five sharpshooters with rifles, one of which is loaded with a blank so the shooters do not know who fired the fatal bullet. Such set-ups have been used mostly for military executions.
Utah is phasing out their use, but the firing squad remains an option there for inmates sentenced prior to May 3, 2004. Oklahoma maintains the firing squad as an option, but only if lethal injection and electrocution are deemed unconstitutional.
In Wyoming, Republican state Senator Bruce Burns said death by firing squad would be far less expensive than building a gas chamber. Wyoming has only one inmate on death row: 68-year-old convicted killer Dale Wayne Eaton. The state has not executed anyone in 22 years.
Additional reporting by The New York Times