It wouldn't surprise me at all if he had no criminal history. I wouldn't go as far as calling him normal, but that's a vague and questionable term. It depends how you define normal. Usually when people brutally murder another human being there are underlying reasons that contribute to that action. Even people described as "explosive" have issues that probably were never addressed. Usually in cases where people snap and kill a partner, such as in intimate partner homicide, there is always some emotion such as jealousy or intense feeling of rejection that results in the person losing control and killing the person they loved. Often there is regret and remorse. Sometimes not. I don't feel that it is common for well adjusted, stable, confident, compassionate, or whatever is defined as " normal" people to suddenly decide to kill someone for no apparent reason. If this is the case then we need to fear everyone around us. Imo there has to be something going on in the persons head to begin with. Pent up anger, fear of rejection, anxiety, life history, no respect for life, or something has to be a factor in order to make one capable of taking a life in the first place. Jmo