Might be worth finding out if you can then accuse him of trespassing to get around the issue of "squatters rights" if applicable.

As I have heard stories of people doing deals with the elderly only to be accused of taking advantage of them.

She was accused in June of discriminating against investors who had renters.  

This way I wouldn't be accused of upfront age discrimination because I never saw their age.

I have supporting emails to validate all my accusations. 

I've had a knife pulled on my and accused of being an f-ing Jew by a sub...Welcome to the world, son.  

Specifically, they're accusing me of not telling them about this refinance (I have documentation of e-mail responses from them), and accusing me of not telling them about a garage on the back end of the 4-unit that we own. 

It's very easy to be accused of steering when you use terms like that.

I didn't want anything to do with that for fear of discrimination accusations etc.

You do not want to be accused of discrimination.Also, I have found that a professional "For Rent" sign with my company name, etc cuts down on the calls as opposed to the red an white generic for rent signs.