NC law? How many peopl can live in 2 bedroom APT? Plz help?

I live in a nice apartment community. However, recently a group of people moved in that have made this formerly nice community a living ghetto. They are loud, have no respect, and more importantly ever since they moved in peoples belongings have gone missing. I know that they have atleast 6 or 7 people living in a 2 bed room apartment. Im not sure how they got away with this, but IM SURE there has got to be a law against this in NC. Anyone aware of such a law? Thanks