Multi-family that lacks documentation

[Forrest Shealy]

I have only done SF in B neighborhoods until now. I am looking at a 10 unit in a C- neighborhood. The price is great. The numbers the current owner is giving me are good enough to leave some margin for error, and there even appears to be upside on the rents. The renovation would be straightforward and reasonable cost. The problem is, they have no documentation. The rent roll lacks detail and is not current. They have no record of depositing the rent anywhere. Even documentation of expenses is coming slow and spotty. 

My broker acts like this is normal in this part of the market. How do I find out if some horrible surprise is lurking? I would really appreciate input!