The Supreme Court on Monday appeared unconvinced that the lethal-injection procedure used for capital punishment nationwide poses enough risk of pain to inmates that it raises constitutional objections as “cruel and unusual” punishment.

The three-drug “cocktail” used to anesthetize, paralyze and then kill death row inmates is the focus in Baze v. Rees, a Kentucky appeal brought by Ralph Baze and Thomas Bowling, two inmates convicted of separate double murders in the early 1990s. Since the Court granted review in the case in September, a de facto moratorium on executions has taken hold across the country. All but one of the 37 states with capital punishment use lethal injections as a requirement or a choice. (Nebraska uses electrocution.)