The US state of Ohio has carried out a death sentence using a single-drug injection instead of the standard three-chemical solution.
Kenneth Biros, 51, was pronounced dead ten minutes after one dose of sodium thiopental began flowing into his veins at the Southern Ohio Correctional Facility. The US Supreme Court had rejected his final appeal two hours earlier.
Experts had predicted that sodium thiopental — used in many parts of the world to put pets down — would take longer to kill than the old method. But the 10 minutes it took Biros to die was about as long as it has taken other inmates in Ohio and elsewhere to succumb to the three-drug combination.
The mother, sister and brother of Biros' victim, Tami Engstrom, applauded as the warden announced the time of death.
"Rock on," Debi Heiss, Engstrom's sister, said a moment earlier as the curtains were drawn for the coroner to check on Biros. "That was too easy."
Ohio's switch to one drug was the result of a botched execution attempt on another inmate in September, but critics of the three-drug method have long argued that it amounts to cruel and unusual punishment in violation of the US Constitution because it can subject the condemned to extreme pain while leaving them immobile and unable to cry out.
The three-drug method consists of sodium thiopental, a common anesthetic, along with pancuronium bromide, which paralyzes muscles, and potassium chloride, which stops the heart. The single-drug technique amounts to an overdose of the anesthetic — a method that injection experts and defense attorneys agreed would not cause pain.
Biros' executioners struggled for several minutes to find suitable veins, inserting needles repeatedly in both arms before completing the process on just his left arm. He winced once, and his attorney, John Parker, said he was concerned by all the needle sticks. But prison officials declared nothing amiss.
"There was no problem with anything in us carrying out the law of this state in this particular execution — none whatsoever," Ohio Prisons Director Terry Collins said. "The process worked as we said it would work."
After the chemical started flowing, Biros' chest heaved several times, and he moved his head twice over a span of about two minutes before he lay perfectly still.
In 2008, the US Supreme Court upheld lethal injection in a case from Kentucky involving a three-drug method similar to the one used in Ohio and practically every other death penalty state. After a seven-month moratorium on the death penalty while the high court decided the case, executions resumed across the country.
In its ruling, the Supreme Court said states would have to change from the three-drug process if an alternative method lessened the possibility of pain.
Deborah Denno, a law professor at New York's Fordham University and a lethal injection expert, said she is highly sceptical that Ohio's single experience will change the landscape around the country. She noted that the Supreme Court questioned the one-drug method, with Chief Justice John Roberts saying it "has problems of its own."
All 36 death penalty states use lethal injection, and 35 rely on the three-drug method. Nebraska, which recently adopted injection over the electric chair, has proposed the three-drug method but hasn't yet adopted it.
Kentucky, Florida, South Carolina, Texas and Virginia are among those that have said they will keep the three-drug method.
Sodium thiopental is a barbiturate often used to anesthetise surgical patients, induce medical comas or help desperately ill people commit suicide. It is also sometimes used to euthanise animals. It kills by suppressing breathing.
Biros killed his 22-year-old victim in 1991 after offering to drive her home from a bar, then scattered her body parts in Ohio and Pennsylvania. Before dying Tuesday, he apologised for his crime.
"I'm being paroled to my father in heaven," Biros said. "I will now spend all of my holidays with my Lord and savior, Jesus Christ."