FInd out who has the deed. IF the Landlord is NOT the owner, get the owner. Does the owner have knowledge and if not, let the owner know how the home is being used and abused.
We had a drug house in our neighborhood and they trashed the home in the front, garbaged never moved and such. So, we got a hold of the owner and just told them straight forward that their home would not be worth a cent if they did not get those trashy people out and within 48 hours, they were gone!