A judge ruled on Tuesday that Montana's lethal injection protocol is unlawful. Judge Jeffrey Sherlock of the 1st District Court of Montana ruled that the state may not use pentobarbital for lethal injections. Pentobarbital is one of the two drugs used in the state's two-drug execution protocol. The ruling stems from a 2008 lawsuit by the Montana American Civil Liberties Union on behalf of death row inmate Ronald Allen Smith.