Missouri has executed its fourth prisoner in four months. Michael Taylor was injected with the lethal drug pentobarbital following his conviction of the rape and murder of a 15-year-old girl. His attorneys had warned the drug, purchased from an unnamed compounding pharmacy, could cause immense suffering. They had also questioned Missouri’s practice of executing prisoners before appeals are exhausted. Late last month, Missouri executed Herbert Smulls just minutes before the U.S. Supreme Court ruled on an appeal.