"He got up in the middle of the night without his prosthetic limbs to retrieve a fan.
He was in the hall outside of the bathroom, heared a noise, and without his legs, he felt vulnerable.
He fired shots.
He then went to the bedroom, to retrieve his legs, and at that point realised his girlfriend was not in bed.
Realising it may be her, He then broke down the bathroom door with a cricket bat, and carried his girefriend down stairs.
He comforted her as she died."
So his defence is to admit that he's the dumbest person in the world