For my story, it's about a serial rapist/killer type villain and the reason why he is that way, is that he was a misfit while growing up, being bullied and persecuted for being 'inferior'. He becomes lonely, especially yearning for the opposite sex as he gets older, and this turns him into what he is, and he targets women that are the type to reject him. So the hero, who is a cop, needs to flush the villain out in order to find out who he is. Not only that but he also needs to get the villain to do something to incriminate himself, so is there as way his weakness can be used against him? I thought of a few, in the past, but I was told by other writers and readers that it made the villain look stupid, that he would fall for such tricks, when he was smart enough to cover his tracks on all his crimes in the first place. I was just looking for suggestions, if there is any way to exploit that weakness, without the villain having to become stupid to fall for it, if that makes sense. Thank you for the input and advice. I greatly appreciate it .