BOSTON — Just one final step remains before a jury is seated in the federal death penalty trial of Boston Marathon bombing suspect Dzhokhar Tsarnaev (joh-HAHR' tsahr-NEYE'-ehv).A panel of 12 jurors and six alternates is expected to be selected Tuesday after prosecutors and Tsarnaev's lawyers are allowed to eliminate jurors for strategic reasons.Judge George O'Toole Jr.