Credit score disqualification, insufficient work history or income, criminal record, etc.

If the previous address is close, march into the court house and look up the criminal and civil filings under the applicant's name.

In talking to the tenant she wouldn't tell me his last name - long story short he was trying to hide his background (multiple criminal, evictions, 5 owi's, etc).  

Example from my last real AD.HOUSE FOR RENT3BR2BAmore infomore infoI WILL ONLY RESPOND IF YOU LEAVE A REAL PHONE NUMBER$50.00 non-refundable application feeTypical Qualifications: 600+ Credit Score| No judgements | No evictions| No criminal background | No smokers| No delinquencies |2 pay stubs| whateverElseIRequire ------------------2) I do this to help reduce the amount of callers that will not qualify.3) If you decide to screen over the phone I ask.

I've looked at tenant screening, mysmartmove, turbotenant, rentprep.It's all a bit overwhelming - I think I want it all - credit, background, eviction, and criminal.  

It could possibly be criminal. 

I would immediately talk to a very good criminal defense attorney and get some advice. 

You can also go to public state records available free online and search their criminal history.  

While a violation by them would result in a possible civil penalty, you are acting as an agent without a license which could result in a criminal action

—In all criminal cases, contempt cases, and other cases filed pursuant to this chapter, if a party has sold, leased, or let real estate, the title to which was not in the party when it was offered for sale, lease, or letting, or such party has maintained an office bearing signs that real estate is for sale, lease, or rental thereat, or has advertised real estate for sale, lease, or rental, generally, or describing property, the title to which was not in such party at the time, it shall be a presumption that such party was acting or attempting to act as a real estate broker, and the burden of proof shall be upon him or her to show that he or she was not acting or attempting to act as a broker or sales associate.