By David Schwartz and Karen Brooks
PHOENIX/AUSTIN, Texas (Reuters) - Arizona is set to execute on Wednesday an inmate convicted of strangling an elderly man 35 years ago and Texas is scheduled to put to death a man convicted of killing his parents and blowing up their house.
Both states plan to perform the lethal injections using pentobarbital, a barbiturate frequently used in executions that has become scarce as major manufacturers have refused to supply it for that purpose.
Some states, including Texas, have turned to other suppliers such as lightly regulated compounding pharmacies to secure drugs, raising the fears of death penalty opponents that use of the alternative drugs will lead to a botched execution.
Edward Harold Schad, 71, is set to be executed on Wednesday morning at an Arizona state prison and Michael Yowell, 43, after 6 p.m. local time at a Texas state prison.
Schad would be the first person executed in Arizona in 2013 and Yowell the 14th person executed in Texas this year. Overall, 28 people have been executed in the United States this year, according to the Death Penalty Information Center.
Schad's attorneys last week sought to delay his execution because Arizona had not provided information about the drug to be used in his execution. But Arizona answered that challenge by disclosing that it had purchased pentobarbital from Lundbeck LLC, a Danish pharmaceuticals company that has since stopped selling the drug for executions.
Arizona inmate Schad was convicted of killing Lorimer Grove, 74, in 1978 and leaving his body in some underbrush near Prescott, Arizona, with a rope still knotted around his neck, officials said. Schad was arrested in Utah after a tipster told police Schad had told him that he was driving a stolen car.
Yowell and two other Texas death row inmates have challenged in part the state's use of a compounding pharmacy to obtain pentobarbital for executions.
Yowell was convicted of killing his parents, Johnny and Carol Yowell, in 1998 and blowing up their home in Lubbock, Texas. His grandmother, who also lived in the home, was killed in the blast. He was not convicted in her death.
Yowell confessed that he shot his father to death after the man caught him stealing his wallet to get money for drugs. He then beat and strangled his mother, according to an account of the case from the Texas Attorney General's office.
"Yowell said that afterwards, in a panic, he ran to the kitchen and opened a gas jet," the account said.
Yowell has asked a federal appeals court to stop his execution in part because Texas turned to a compounding pharmacy for pentobarbital, the single-dose drug it uses in executions, after its supply expired in September.
Yowell argued in part that using drugs from a compounding pharmacy and not a manufacturer raised the risk of defective ingredients that could cause him pain in violation of the U.S. Constitution's ban on cruel and unusual punishment. A federal judge has rejected that argument.
Lawyers for both men scheduled to die have appealed to higher courts, which could still stay the executions.
(Reporting by David Schwartz in Phoenix and Karen Brooks in Austin, Texas; Editing by David Bailey, Greg McCune and Lisa Shumaker)