After further consideration, I was pleased to remember that this is a forum for rational and responsible people, not those it-should-be-illegal-to-offend-me folks.My "crime free" lease addendum includes provisions allowing an eviction over suspicion of criminal activity, so I agree with @Chase Gochnauerthat the intent is to deal with disturbances, not provide for a penalty.  

I'm currently a secretary with a Bachelor's Degree in  Criminal Justice. 

Mom and Pop landlord are intentional targets of these criminals and fell victim due to their own short comings.

As far as performing our due diligence can we perform criminal checks or should we keep as far as credit checks ?

I am a Criminal Defense Attorney by trade to I try plan out as much as I can because I hate to be cause off guard.

In the judicial section you can do a criminal conviction and also pending case look-up.

Also depending on your finishes you may end up with renters that have a criminal history.

While I've found many references to looking for 'x' number of years of rental history in other posts, I can't find anything that directly answers this nuanced question:We have a couple that meets our income, criminal (lack thereof), number of occupants, pet policy, etc.  

The owner of the house died, the house is criminally underwater, deed transferred to unsuspecting ex-wife of owner and she plans on letting it foreclose since ex-wife thought she had nothing to do with this house any longer.  

However, if you agree to this and it's found out, you may face criminal charges.