Very difficult to confirm and confront as there is ALWAYS MOLD.This mold was not visible.

And please know, I am asking legitimately with interest in the answer, not confrontationally as many people like to be on these forums. 

I think if you confront the tennant you'll set yourself up for a much better relationship.

All this leads to is a confrontation for the sake of fighting. 

And the stronger words help me build the right vocabulary when I have to be the one confronting the tough situation.

-Maybe you should go confront the person and do something about it yourself.

At one point when I was there to collect rent, I witnessed a 50-something year old guy coming out of the back bedroom area, and when I confronted him asking "What the hell are you doing here?"

I see now the confrontational attitude, you're trying to impress while you cut a deal in the forms.

She became more confrontational, she NEVER returned my calls inquiring about status of past due payments and generally became very difficult to deal with.  

The downstairs tenant has reported this to me, and I have confronted the new girl and let her know that I won't stand for any bad behavior.