OKLAHOMA CITY—As many as 10 death row inmates in Oklahoma, more than one-fifth of the state’s prisoners condemned to die, could escape execution because of a recent U.S. Supreme Court ruling concerning criminal jurisdiction in Indian Country. The inmates have challenged their convictions in state court following the high court’s ruling last year, dubbed the McGirt decision, that determined a large swath of eastern Oklahoma remains an American Indian reservation. The decision means that Oklahoma prosecutors lack the authority to pursue criminal charges in cases in which the defendants, or the victims, are tribal citizens. Among the inmates likely to get a new trial in federal court is Shaun Michael Bosse, 38, who was convicted and sentenced to death in the 2010 killing of Katrina Griffin and her two young children. The victims were all found inside a burning mobile home near Dibble, about 35 miles (56 kilometers) south of …