An undated handout photo shows a lethal injection room at a U.S. prison.
An undated handout photo shows a lethal injection room at a U.S. prison.

The United States Supreme Court has upheld the use of a controversial drug in executions by lethal injection.

In a 5-4 ruling Monday, the court's five justices said that the use of the sedative midazolam does not violate the Constitution's Eighth Amendment ban on cruel and unusual punishment.

Death row inmates from the Midwestern state of Oklahoma argued that the sedative, used as part of a three-drug combination for lethal injections there, did not always induce a deep unconsciousness that would prevent them from experiencing the pain from the paralytic and heart stopping drugs which follow.

Oklahoma used the drug during the botched execution of death row inmate Clayton Lockett, who groaned and lifted his head after the combination was administered. It took a staggering 43 minutes for him to be pronounced dead after the first injection.

In her dissent, Supreme Court Justice Sonia Sotomayor likened the use of the controversial drug to being "slowly tortured to death, or actually burned at the stake.''

Justice Samuel Alito, who wrote the majority opinion, said arguments the drug could not be used effectively as a sedative in executions is speculative. He called Sotomayor's dissent "outlandish."

In a separate dissent, Justices Stephen Breyer and Ruth Bader Ginsburg said it is time for the court to debate whether the death penalty itself is constitutional.

Public opinion studies show that support for the death penalty among Americans is lower than it once was. But it remains strong, at about 60 percent.

Several states that once had the death penalty now have either suspended its use or dropped it altogether. Only 32 states continue to apply capital punishment.