Investigators began to suspect that debbie may have intentionally poisoned herself. >> it made me very angry. i mean, if anybody knew me, they would know that i would never do this to myself. i mean, first of all, i wouldn't do it to my children. second of all, it's just, if i wanted to hurt myself, i wouldn't do it this slow, torturous, painful way. >> tony suspected sarah smith's family may have had something to do with the poisoning. sarah smith was tony's patient who had died during surgery. >> anthony thought that dan smith was trying to get even with him for taking his wife away from him...