Need more facts. Did the man have good reasons to drown the dog and girl? Some women will game a poor guy and steal his money driving him into an unstoppable fury. Get the criminal history of both persons and investigate all facts thoroughly. Did she promise him daily recreation for free room and board? Did he get fooled into falling in love with her? AT 40 yo why couldn't he find a nice 20 yo? Glad I don't know these Kailua folks and am not a detective.