FLORENCE, Ariz. -- Facing a nationwide shortage of a lethal injection drug, Arizona has taken an unusual step that other death penalty states may soon follow: get their supplies from another country.
Such a move, experts say, raises questions about the effectiveness of the drug. But it also may further complicate executions in the 35 states that allow them, as inmates challenge the use of drugs not approved by federal inspectors for use in the U.S.
Arizona said Tuesday that it got its sodium thiopental from Great Britain, the first time a state has acknowledged obtaining the drug from outside the United States since the shortage began slowing executions in the spring.
"This drug came from a reputable place," Chief Deputy Attorney General Tim Nelson said. "There's all sorts of wild speculation that it came from a third-world country, and that's not accurate."
Nelson said the state revealed the drug's origins to let the public know that its supply is trustworthy and to dispel rumors. However, he did not name the company that manufactured it.
Without assurances of the drug's quality, many questions will be raised, including its effectiveness and how it should be handled, and would serve as a basis for lawsuits, said Deborah Denno, a law professor at Fordham University.
"The impact could be huge," Denno said. "The source of the thiopental is critical."
Tuesday night, Arizona executed Jeffrey Landrigan for a 1989 murder in the state's first execution since 2007. Landrigan died by injection at a state prison in Florence at 10:26 p.m. after a stay issued by a federal judge was lifted by the U.S. Supreme Court.
Landrigan's lawyers had argued he could be suffocated painfully if the sodium thiopental doesn't render him unconscious. In lethal injections, sodium thiopental makes an inmate unconscious before a second drug paralyzes him and a third drug stops his heart.
Hospira Inc. of Lake Forest, Ill., the sole U.S. manufacturer of the drug, has blamed the shortage on unspecified problems with its raw-material suppliers and said new batches will not be available until January at the earliest.
There are no FDA-approved overseas manufacturers of the drug.
The limited supply has also directly affected executions in California, Kentucky and Oklahoma, and may affect executions in Missouri, which says its supply of sodium thiopental expires in January.
California officials say they acquired a dosage of 12 grams in September with a 2014 expiration date. But there was some dispute about the source. Hospira said its remaining supplies expire next year and California could only have obtained it elsewhere.
The state prison system would not address the discrepancy. "The state obtained the sodium thiopental lawfully from within the United States," Terry Thornton, a corrections spokeswoman told The Associated Press.
Ohio, which spends about $350 for the drug for each execution, ran out of the amount prescribed by state procedures just three days before a May 13 execution. The state obtained enough in time but won't say where.
A few weeks ago, Kentucky's governor held off signing death warrants setting execution dates for two inmates because the state is almost out of sodium thiopental. The state's lone dose expired Oct. 1.
Officials say they have tried unsuccessfully to get the drug from other states, and have gotten calls from states looking for it.
In August, an Oklahoma judge delayed the execution of Jeffrey Matthews when the state tried to switch anesthetics after running out of its regular supply in August. Matthews was convicted of killing his 77-year-old great-uncle during a 1994 robbery.
Oklahoma finally found enough sodium thiopental from another state, but the court-ordered delay continues.
The controversy could end if Hospira resumes making the drug next year as indicated, or states could switch to another drug.
At least 15 states, including Arizona, Florida, Missouri, Texas and Tennessee, might be able to switch drugs without a new law or administrative process, death penalty expert Megan McCracken said.
In Arizona, officials at the state prison waited for the high court's decision for much of the day. The execution had been set for 10 a.m. Tuesday, but a ruling by a federal judge in Phoenix that had been upheld by an appeals court panel put the execution on hold until the evening.
The delay, prosecutors say, is one reason the public has lost some faith in the criminal justice system.
"We're 20 years in and we're not arguing over guilt or innocence," said interim Maricopa County Attorney Rick Romley, whose office prosecuted Landrigan in the 1989 killing of Chester Dyer during a robbery. "We have lawyers fighting lawyers."
In recent years, lethal injections have run into high-profile problems, including botched executions.
Ohio and Washington have switched from a three-drug method to a single, powerful dose of sodium thiopental. The change helps avoid litigation over pain that inmates could suffer from the second and third drugs if they haven't been knocked out.
The switch doesn't affect the drug's administration, which has led to a number of fumbled executions, including a September 2009 procedure in Ohio in which the governor stopped an execution after two hours when officials couldn't find a usable vein.
The issue will come down to whether an overseas version of sodium thiopental would be equivalent to what the FDA has approved here, said Ty Alper, associate director of the death penalty clinic at the University of California-Berkeley.
"It really opens the door to Eighth Amendment challenges that go to the heart of whether executions work the way they're supposed to," he said, referring to the amendment about prohibiting cruel and unusual punishment.