By Brendan O'Brien
(Reuters) - Texas on Thursday executed a suspected serial killer convicted of stabbing a teenage girl to death, a day after a federal appeals court rejected his challenge over the drugs to be used in his lethal injection.
Tommy Lynn Sells, 49, was pronounced dead at 6:27 p.m. CDT after receiving a lethal dose of drugs at a state prison in Huntsville, Texas, the state's Department of Criminal Justice said. He made no final statement.
Sells was the 15th person executed in the United States this year and the fifth in Texas, the state that executes more people than any other in the nation, according to the Death Penalty Information Center.
Attorneys for Sells had challenged the state's lack of disclosure about the supplier of the drugs to be used to kill him, winning a temporary stay from a federal judge in Houston that was overturned hours later by a federal appeals panel.
The appeals court said the case might be different if the state were using a drug never before used or unheard of, whose effectiveness was completely unknown, which was not the case.
The U.S. Supreme Court denied his last appeals about an hour before the execution.
After the stay was denied, attorneys for Sells said they hoped the U.S. Supreme Court and Texas courts ultimately will find transparency essential to protect the rights of prisoners.
"Without transparency about lethal injections, particularly the source and purity of drugs to be used, it is impossible to ensure that executions are humane and constitutional," attorneys Maurie Levin and Jonathan Ross said in a statement.
Sells was convicted of stabbing a 13-year-old girl to death and attempting to kill a 10-year-old girl on New Year's Eve of 1999 at the Del Rio home of a man who owed him drug money, according to court documents.
Sells went to the house to sexually assault the girl as pay-back for the drug debt. He broke in, found her sleeping on a bunk bed and began assaulting her. When she awoke, he stabbed her multiple times and slashed her throat, killing her, court documents showed.
Sells then slit the throat of a 10-year-old girl who was sleeping in the top bunk. After he fled, that girl walked to a nearby neighbor's house to get help, court documents showed.
According to various media reports, Sells confessed to as many as 70 murders, starting when he was 16 years old.
Texas has executed 513 people since the U.S. Supreme Court reinstated the death penalty in 1976.
(Reporting by Brendan O'Brien in Milwaukee; Editing by James Dalgleish and Eric Walsh)