Example of "bad-boy" behavior could be fraud or intentional misrepresentation by the borrower, gross negligence, criminal acts, etc.

The reports will typically include credit, criminal and evictions history if they are thorough.

We are so lucky in Virginia that all our civil and criminal records are not only public, but we are able to easily view them on-line. 

Typically you want to have a certain amount of income (verified by pay stubs), approach to real estate rental history (i.e. no eviction), credit background check (some use FICO scores), as well as any criminal background/history (no to little background).- In addition to the above, I ask for an explanation in my application.

As Tim said, find a super reliable screening solution and be sure to run credit, criminal, and eviction.  

I would only utilize that service for tracking criminal history checks and credit checks to vet those aspects of the tenant.

Do they have a criminal history or other black marks like bad credit?

@Harry Karambizi, Not PAYING taxes is a civil case, not FILING a personal tax return is a criminal felony. 

I am telling them all the standard requirements before even seeing the unit, 3x rent, good credit, no criminal record and no evictions.Thanks 

@Theresa Harris They're criminally high.