Who is Father Murphy from Cathedral and what is their importance?

Father Murphy is an Irish priest, as well as an assistant to the Cardinal. When the Cathedral is taken, Murphy is in the midst of the St. Patrick's Day mass. Even though he helps Maureen and Baxter escape, he is loyal to his Cardinal and refuses to leave the Cathedral without him. Murphy is handcuffed to a ladder in the upper areas of the Cathedral during the attack, and he is shot by the ESD who believed he was a Fenian.