LITTLE ROCK, Ark. (AP) — After surrendering its supply of a lethal injection drug to federal agents in 2011, Arkansas turned to a somewhat surprising place to look for another drug: a list from lawyers for several death row inmates.

The state Department of Correction told The Associated Press this week that it decided to use phenobarbital after attorneys for several death row inmates mentioned in a lawsuit that it might be an available drug. Phenobarbital, which is used to treat seizures, has never been used in a U.S. execution, and critics contend that a drug that’s untested in lethal injections could lead to inhumane deaths for condemned prisoners.