If they are VERY professional, they will have their processes in writing as verification that policies are enforced equally and fairly by their entire staff.6.

You may not collect anything, but it will sit on his credit report and prevent him from getting a car loan, home loan, or scamming another landlord.

This is because real estate is capital intensive and lack the cash to buy larger assets or credit worthiness.  

What documents do they require, what credit scores do they allow, how do they verify previous rental history, etc.?

Quote from @NA Hirsch: What service do you recommend for doing a soft pull on a potential borrower's credit?

I think I would be more worried about the credit than I am about the DUI.

Be nice to get them come down in price or give me seller credits. 

Some lenders offer construction loans, or you might consider a home equity line of credit (HELOC) after acquiring the property if you build equity quickly.Long-Term Goals: Consider how this fits into your long-term investment strategy.

My first property was tough, (credit not in place was a challenge - luckily, got some help on this!) 

As long as the property generates enough cash flow, you may qualify based on the asset alone.Another route is to explore portfolio loans from local banks or credit unions.