Though contraversial, Oklahoma's lethal injection cocktail does not violate the Constitution's ban on cruel and unusual punishment.
Glossip v. Gross, 2015 BL 206563, U.S. No. 14-7955
Justice Alito, writing for the majority, said that the challengers did not meet the burden of proving that Oklahoma's protocol poses a demonstrated serious risk of inflicting pain and suffering when compared to known and available alternatives.
Anyone making an Eighth Amendment challenge to the drugs used in a lethal injection cannot prevail unless they can identify an available alternative that has a substantially less severe risk of pain. This seems to give states a significant amount of leeway regarding their specific lethal injection cocktails.