Have a degree in Criminal Justice, life experience, and currently still active duty Marine.

You can reject a Section 8 applicant for the same reasons you reject other applicants: credit score, Landlord reference (or lack thereof), criminal history, etc.

Criminal background: No violent felonies within the last 7 years.

I notice that most of the examples of references "saving" someone from making a bad decision on a tenant involve instances in which the problem would have been detected with a simple background, criminal, or credit check.  

If she has no evictions or criminal history that is great.

After all, if criminal behavior is the culprit then why not advocate for prosecution of criminals?

Basically after we mutually agreed that she would leave after two weeks we discovered her criminal background through a reverse phone lookup.

Be careful contacting delinquent borrowers in states where your actions could be construed as foreclosure consulting, which may require a license and may subject you to civil/criminal penalties if you run afoul of the law.

The criminal investigator is in communication with the victims who filed. 

Truly appreciated.Mike You should check if he has a prior record or criminal history.