By Tim Gaynor
PHOENIX (Reuters) - The condemned killer of two convenience store employees was executed by lethal injection on Tuesday after losing an 11th-hour appeal that raised questions about the origins of drugs used in putting him to death.
A jury convicted Eric John King in 1990 of two counts of first-degree murder in the shooting deaths of convenience store clerk Ron Barman and the store's security guard, Richard Butts, during a December 1989 robbery that netted the killer $72.
King, 47, was executed at a state prison in Florence, Arizona, southeast of Phoenix, at 10:22 a.m. local time, according to state Attorney General Tom Horne.
"This morning the state of Arizona fulfilled its most somber obligation to protect public safety by executing convicted murderer Eric King by lethal injection," Horne said in a statement, adding that he was a witness to the execution.
King was the first prisoner put to death by Arizona this year. His last words were "No," the state Department of Corrections said in a news release.
He requested a final meal of catfish, collard greens, candied yams, a tomato, corn bread, chocolate cake and a pink grapefruit, washed down with cream soda.
According to prison officials, 130 people remain on death row in Arizona, with the next execution set for April 5.
King's execution was caught up in a simmering nationwide legal debate over suitable alternatives for dwindling U.S. supplies of sodium thiopental, a key ingredient in a widely used three-drug lethal injection "cocktail."
A domestic maker of the anesthetic, which renders the prisoner unconscious, has announced it was discontinuing its manufacture, leading to shortages.
King's lawyers had sought a stay of his execution pending an investigation into how Arizona acquired its supplies of sodium thiopental and a second drug in its lethal injection series, pancuronium bromide.
They argued that the Corrections Department violated state law when it imported the two drugs, which were described in shipping documents as being for animal use. The appeal was denied by the state Supreme Court.
Corrections Department chief Charles Ryan is considering a change to using a single drug in its executions, a spokesman said.
In Texas on Tuesday, lawyers for two death row inmates filed a lawsuit challenging a decision by that state to switch from using sodium thiopental to pentobarbital, which is often used to euthanize animals.
Attorneys for Cleve Foster and Humberto Leal argued the new Texas protocol should be nullified because the state failed to comply with procedural requirements in making the change.
Michelle Lyons, a spokeswoman for the Texas Department of Criminal Justice, said the agency was reviewing the lawsuit and had no immediate comment.
(Additional reporting by David Schwartz in Phoenix and Corrie MacLaggan in Austin; Editing by Steve Gorman)