He has a CONCEALED CARRY (we are in AZ).  

I live in the south, a castle doctrine state, and have my concealed carry permit.

Also, being in Texas, we conceal carry as a precaution.

Self defense of your self or others is a reason that concealed carry has gotten so "main stream" of late.

But, I can count on one hand with fingers left over the number of times I have seen a loan called for no other reason than title being transferred over the last 25 years.Putting a property in a trust for the purpose of concealing any material fact from a lender is an act of fraud.

It's small, concealable, and very reliable.

Also, when conducting due diligence, is there anything that sellers often try to conceal that I should be on the lookout for?

A property manager friend of mine got robbed at gunpoint collecting money and the funny part is he had concealed carry and froze cant shoot people in the back with the liberal mindset even when they are committing a violent felony you'll go to jail for murder now a days its sad . 

@Matt K.You conceal-carry in a 2-door Lexus in the Burgh hoods and the po-po stops you, your life doesn't matter whatever color you are.

It's now their word against the former landlord's, with the understanding that the landlord would have had financial incentives to lie or conceal important and unfavorable facts about the lease to push the sale through and get her/his money.If you don't have these letters of estoppel in hand, in short, the tenants can have you over a barrel if they decide to lie about their agreement(s) with the former landlord.This is why the general rule is always to talk to the tenants, either personally or through a representative, before the sale, to collect these letters of estoppel.On the other hand, for all I know, you may have collected these letters of estoppel.