Whether killing a person via intravenous poisoning qualifies as cruel and unusual remains, for the moment, an open question. Beginning in late February, the United States District Court for the Western District of Oklahoma heard testimony at the trial of Glossip v. Chandler, an eight-year-old lawsuit filed on behalf of a group of death-row inmates that seeks to prove that Oklahoma’s current lethal-injection recipe—500 milligrams of midazolam, followed by 100 milligrams of vecuronium bromide, followed by 240 mEq potassium chloride—violates the Constitution’s Eighth Amendment ban on cruel and unusual punishment. The case focuses on the constitutionality of midazolam, a sedative with limited anesthetic and no analgesic properties that critics argue results in slow and painful deaths for those poisoned with it.

Recent events have lent the case a special urgency. Last year, John Marion Grant was discovered to have inhaled his own vomit before dying once Oklahoma authorities had injected him with the midazolam-led cocktail, a death that witnesses described as particularly gruesome. Nevertheless, another three executions deploying the same method have gone forward since Grant’s.

The suit will be the latest and most noteworthy in a lengthy lineage of so-called method-of-execution litigation, or legal challenges to capital sentences under the Eighth Amendment. In some states, evidence that lethal injection is inhumane has already led to de facto shutdowns of execution chambers—California, for instance, hasn’t attempted an execution since a sprawling 2006 method-of-execution lawsuit unearthed disturbing facts about the state’s protocol. probably can’t bank on similar results