In Vegas, it was great at first, then my tenants started losing their jobs one by one, and then I ran into a scam artist, which now I know to do a criminal background too on a prospective tenant.

I think thats the game the criminal bankers and wall street are playing with full support of the government they bought and paid for.

Turns out the job someone did to finish it is so poor it should be criminal.

As I understand it, violating this would be a civil affair and not a criminal action so therefore isn't really "illegal".

The married couple are both professionals and claim to earn a gross monthly income of 3x the rent amount (to be verified by me).I have a rigorous screening service for criminal, credit, eviction, and employment verification which I will use to process applications for the married couple and their qualified co-signer.I've read that renting to a tenant undergoing a short sale is fraught with risk because the short sale may never occur, which would result in foreclosure and could pressure the tenant into bankruptcy during the lease period. 

I.e. verify that the tenant has been paying on time, do a background check to see if the tenant has a criminal history and verify that they have good credit.  

The tenant screening should include a full credit check, criminal background check for felony at the state and federal level, homeland security check and sexual predator check.  

I simply offered him an application (which he would not take, a real red flag as I find those with serious eviction, credit issues, or criminal history treat my app like a vampire does daylight, literally moving away from it....)...Short answer--it does not matter much to me--all up front or monthly...

That is not a criminal matter, it is a contract issue between two parties. 

credit  criminal and make sure there is something hidden .. you would be shocked at what is in peoples closets... it does amuse me that people put tenants through the ringer but wont' ask for this simple stuff for people they are going to lend a bunch of cash to.