I think that many people assume that husbands who are not physically abusive or don't threaten to kill their wives are not dangerous.
From what I've observed, complete selfishness and lack of normal human emotions such as compassion are better indicators that a man might kill his wife. Men who do this have spent their lives putting on an act. They pretend to be outgoing, friendly, charismatic, caring , loving husbands and fathers. When the facade starts to crumble, the wife would be the first to see it. That is when she becomes expendable...and he becomes a killer.
JMO
Susan