I'm trying to kill Prescott Cormic. I already encountered him at the beach, he ran and I killed all the guards. Talked to Lexington, then went to Cormic's house......killed that guard. I've been beating Cormic for the past 20 minutes....his life bar is empty but he keeps getting up! What gives?? I assume the shield with his family crest is something I have to loot from his dead body so, how do I kill this guy? Help please!