FLORENCE (AP) - A man convicted of killing two people in a 1989 Phoenix convenience store robbery was executed Tuesday despite last-minute arguments by his attorneys who raised questions over one of the lethal injection drugs and said there was "substantial doubt" about his guilt.
Eric John King's death at the state prison in Florence was Arizona's first execution since October and one of the last expected to use a three-drug lethal injection method.
As the death chamber's curtains opened, King smiled broadly at someone he knew and waved with a hand under a sheet that covered him to his neck. When asked if he had any last words, the 47-year-old calmly and firmly said, "No." He then looked around at the estimated 30 witnesses in the room, at times smiling.
Corrections Director Charles Ryan announced that King was declared dead at 10:22 a.m.
King had maintained his innocence since his arrest, and his lawyers fought to get his sentence reversed or delayed.
Defense attorney Michael Burke said after the execution that there is no way to know whether King experienced pain after first being injected with sodium thiopental, a sedative that Burke has argued could be ineffective. The second drug paralyzes the inmate before potassium chloride is injected to stop his heart, so if the sedative doesn't work through the entire procedure, King could have been in pain without any way to show it.
The Arizona Supreme Court declined to stay King's execution Monday after Burke argued that the state should wait until it enacts its new lethal injection protocol. The U.S. Supreme Court refused to intervene.
Ryan announced Friday that Arizona will switch to using just one drug in an effort to allay any "perceived concerns" that sodium thiopental is ineffective, but only after the scheduled executions of King and Daniel Wayne Cook for Lake Havasu City on April 5.
Burke had argued that the Department of Corrections may have engaged in fraud when it imported the sedative from Great Britain by listing it on forms as being for "animals (food processing)," not humans. The state said the mislabeling resulted from a clerical error.
Arizona obtained the drug legally, Assistant Attorney General Kent Cattani said.
Georgia's supply of sodium thiopental was seized by federal Drug Enforcement Administration agents on March 15 over questions about how it was obtained.
The drug is part of the three-drug lethal injection method used by nearly all 34 death penalty states, but it became scarce last year after the sole U.S. manufacturer stopped making it.
Some states started obtaining sodium thiopental overseas, and lawyers have argued that potentially adulterated, counterfeit or ineffective doses could subject prisoners to extreme pain.
Texas and Oklahoma recently announced they are switching from sodium thiopental to pentobarbital in their three-drug protocol. Ohio has switched to using only pentobarbital for its executions, and Ryan said that's the drug Arizona might start using.
Burke also was unable to successfully argue that King be granted clemency at a hearing Thursday. Burke had argued that the two key witnesses who testified against King at his trial have changed their stories, that no physical evidence exists and surveillance video used at trial was of extremely poor quality.
King was convicted of fatally shooting security guard Richard Butts and clerk Ron Barman at a Phoenix convenience store two days after Christmas in 1989. Butts and Barman both were married fathers whose families have testified that their deaths in a robbery that netted just $72 devastated them.