I don't know why it's so hard to find decent lawyers and accountants, but it is.Can anyone recommend a decent CPA to me?

And hire a lawyer or eviction specialist to deal with it.

Whether its a "sole proprietorship" "s corp" or "c corp" you should ask a lawyer and a cpa. 

I would be tempted to hire a lawyer :) If they have that many units they have resources and know the law.

If there are any Realtors, Contractors, Wholesales, Flippers, and Buy and Holders, as well as Lawyers, CPA's and anyone who loves real estate—did I get it all—lets talk!!!

I am not a lawyer (and nothing here should be considered legal advice) but my understanding is if it is not recorded, it is not a lien against the property.

I'm a lawyer in the area, as well as a homeowner.  

So my recommendation is if you're going to do it, plan for how you would all part ways ahead of time and each have your own lawyers and document everything.

This is a situation where if you are able to get it under contract/purchase-n-sale agreement.... you then need  to invest a few bucks with a lawyer and see what the absolute legal situation is with evicting the son.  

I'm no lawyer, but I did not find anything in the lease about transfering ownerhsip.