John David Duty (April 25, 1952 – December 16, 2010) was an American who was executed in Oklahoma for first-degree murder. According to the Oklahoma Department of Corrections, he is the first person in the United States to have been put to death with pentobarbital. A nationwide shortage of sodium thiopental led the state to incorporate the substitution into their protocol for lethal injections. Duty's case gained media attention because pentobarbital had typically been used to euthanize animals.