Also when you buy do due diligence on leases and length of occupancy. 

You need to be careful that the sale is "arms-length" and is not just a smoke screen.

. - actually, some of the "foreclosure mill" attorneys can be contacted, as long as the person contacting has the borrower's authorization to release information properly completed and signed, as well as some sort of agreement with the borrower on an arm's length purchase and ability to close quickly.

Make sure that the doctor is local, license included for you to verify, and that they indicate their relationship and its length with the tenant. 

@Nghi Le I'm not going to comment on whether she can "go ahead and make the purchase," but from a gift tax perspective, unless her parents have already gifted their annual exclusion, gift tax will be a non-issue.The difference between non-family purchases is that they are done at "arms length" meaning that the purchaser and seller do not share an interest of any kind.

Also the length of the meeting generally can be 45 to over an hour in length depending if you hit it off or not.

I'm not sure she has cleaned his property yet but he has spoken to her at length I think about what she can and can't do and what she generally charges I think.

My sister is going to purchase the property from my father at fair market value, so the arm's length restrictions will not apply (and lets assume they won't for the conversation).I don't want my parents to pay commissions on the deal, and I'm trying to figure out the cheapest/most effective way to go about the sale.

strictly in an accounting sense you'd debit a current asset/ cash account and credit either a short or long term liability account depending on the length of your leases.

Originally posted by @Matthew Paul:bouncing a check is a criminal offense , tell the guy that you want to void the lease or you will prosecute  for passing bad checks .In some states, if the recipient of a check agrees to hold it for a specific length of time and then it bounces, the courts have held this to be a LOAN.