Crime shouldn't be seen as something good, and I don't think that there is any benefit in crime, and this was why the law was made because crime has been a disadvantage to the society and threat to human lives. A society without crime will be said to be a peaceful one, and that is why you see that there are wars everywhere and all sort of evil deeds.
OP, can you tell me where Arm robbing, kidnapping, killing and raping has a positive effect on the society. Anything crime is evil, and it is not of God but of the Devil, because the bible let us to know that the devil came to steal, kill and destroy.
It's very hard to see any thing good coming out from crime. In fact, even if there's positive impact of it in our society, it doesn't worth discussing considering the damages it could caused. I understand the Op point because I remember reading somewhere that the presence of crime help to improve the security measures in our society but I don't see that as a valid reason or as a positive impact based on what it takes to intensify the security system and what it'll cost the society.
We can not refute the fact that after crime security measures are being intensify but that alone is a negative impact on its own because it will cost the victims emotions and finance to improve the security. Fear will be created in the society and people would feel unsafe in their own society thereby affecting the living standards. Whatever angle one is talking from, crime should not seen as something that can impact our society positively.