In my opinion Lydia's husband should be arrested and tried as the person responsible for her death. The main reason is that he knows that Lydia had taken an overdose of slepping pills and he did't call for an ambulance. He could avoid it by taking his wife to a psychologist, because he knows that Lydia tried to kill herself a few times. Maybe she had problems with herself. In his defense i can tell that he could have had enough of his wife's behavior. She was very attentive and she took every decision of her husband as a reason to kill herself.