Paul E. Plunkett was at home in the courtroom.During his decadeslong career in the law — as a private attorney and prosecutor and later as a federal trial judge — Plunkett thrived on trials.“He loved trials,” Plunkett’s son, Andrew M. Plunkett of Childress Loucks & Plunkett, said Tuesday. “He loved the art of the trial and he loved spending time with his jurors.”Unlike ruling on …