This would probably rate a good "Columbo" episode on its own. Again, McBain here introduces the question of whether to believe the worst in people (though for Carella, unlike Kling, it is his job to thoroughly eliminate the possibility of murder.) Since the wife is a key suspect, it also opens up the question of marital loyalty (How well do we know the people who share our lives, really?) in a way similar to the Kling subplot.