Max Fisher in Vox:
An execution in Oklahoma went disastrously wrong on Tuesday night, when a state corrections department doctor injected death row inmate Clayton Lockett with a secret and untested chemical cocktail that was supposed to kill him quickly and painlessly. About 15 minutes into the execution, it became gruesomely clear to observers that Lockett was conscious, seizing, and in what appeared to be tremendous pain. Officials halted the execution, but 43 minutes after he had been first injected, Lockett died of a heart attack. A second man who was to be executed the same night, Charles Warner, has been granted a stay of execution for two weeks.
Oklahoma was using the experimental formula because pharmaceutical companies increasingly refuse to supply “safe” lethal injection chemicals. That's left capital punishment states to choose between executing inmates under dangerous conditions or not executing them at all. Many states have chosen to go ahead, and some have adopted secrecy laws that shield the chemical compounds used for the executions.
The key chemical in lethal injections is sodium thiopental, originally invented as an anesthetic. But US manufacturers of the drug have been increasingly refusing to sell it, either out of opposition to the death penalty or concern about association with executions. In 2011, the last US supplier, a company called Hospira, stopped making it.