Inheriting a problem tenant after closing

[Damon Diddit]

I currently have this property under contract, expected to close within 3 weeks. There's a tenant that's month to month, rent is at least $800 below market rent, so I told the seller I need that unit to be vacant. He delivered a 60 day notice to quit, to tenant. Here's a little background on Tenant situation...has 2 or 3 young kids, an adult sister, an aunt with her male friend and the lessee has a male friend, that all appears to live in the apartment but aren't on the lease. When entering the apartment, it just feels like a house full of squatters. The living condition is terrible as the apartment is poorly maintained by tenant and poorly managed by landlord [seller]. From my understanding, no one is employed, they are somehow current with the rent, but they are definitely not someone I would offer a new lease...not even at market rate.  There's no way I can keep the house above water with that rent let alone consider any positive cash flow...so I need them out! To this point they have been progressively uncooperative, which has me really reconsidering the deal. I have no experience with tenant evictions and after some due diligence, it could take at least 3 months, until... depending on the judge. Also New Jersey is a Tenant friendly state. The property itself is a good deal, there's a lot wear and tear in apartment so will definitely need some serious renovation work, but mostly cosmetic. If I can get around this situation, it would be worth carrying some costs for a couple months but if eviction prolongs, a good deal will go bad quick. Does anyone have experience with tenant evictions in Newark? Does anyone have any suggestions, advice or a strategy to share with me? Any comments is much appreciated. 

Thanks in advance