Have a lawyer send a letter that if the behavior does not stop, you will be issuing a notice to quit.

Don't reward their bad behavior by paying them!

I’ve gotten pretty good at predicting behavior, so it’s easier to select good tenants.

., "pay" for your conscience - self manage, or find a property management company that wants to manage the unit based on your idea of ethical behavior rather than market behavior. 

I have his behavior on a record.

If she lies about it then I definitely would pass on her, but if she admits her past foolish ways and has all appearance of current responsible behaviors and succeeding in life then what more do you want ?

There is no pattern or bad behavior.   

However, no person on this forum really knows your investment plan, so if this deal fits into your predefined real estate investing plan, then go for it, especially if you know developers prefer two lots over one.Often time I see this behavior with stock traders.

While we fell in love with this child from the beginning, it quickly became apparent that he had severe emotional, developmental and behavioral problems,  He was the kind of kid who got expelled from kindergarten. 

I think they are sleezy in their overall behavior.