Buying a duplex with a hostile tenant

[Meeno T.]

I am looking at a duplex in a B+ Neighborhood located in a C- city.  Here are the numbers:

70k purchase from an investor who bought it from a sheriff's sale.  Similar unit down the street sold for a little over 100k.  Duplex built in 90's, had previously sold in the 300's during heyday but I believe market has bottomed out.

Unit one rented at $750 (1bd)

Unit two hostile tenant who would be evicted before closing. (2bd). Can probably rent for 1100 in good condition

Taxes are high: 4500, but appeal has been filed.

HOA: 70/mo (trash, lawn, snow only).

This is my first investment purchase.  I have a good feeling about the area but worried about the damage in the hostile unit.  Since it's relatively new I figure new bath, kitchen, floors and paint at worst.  

This would produce a positive cash flow from the outset assuming I get a rehab and tenant quickly, but want to make sure I'm not missing anything?