In most states it depends on if they are on the lease or not. If they are the owners would have to evict (and that means all tenants) based on money (not paying rent) or issues related to law such as destroying the property or drug issues related to the property. If they are not on the lease then most states allow you to get a court ordered eviction notice based on the same criteria. You would need to seek a lawyer in your area to see if you can and what issues you can raise. If he is just a bum and you let him stay for free from day one, you may have a problem.