This also makes me nervous because of the lower profit potential/ smaller pool of potential buyers/ criminal activity etc. 

I think Downtown Detroit is not considered cool, there is some security/criminality issues, but I heard rumours that artists/tech/financial employees are moving in. 

I have parents cosign and just do a criminal check on the students.  

After all, our criminal and civil courts are full of very knowledgeable and extremely competent attorneys who simply differ on the meaning of a word or two in a contract or civil or criminal statute. 

For MO criminal hisotry without cost to you, and quick look-up: https://web.mo.gov/doc/offSearchWeb/search.jspPut in the applicant's Name.

No criminal history / Are they responsible? 

No offence to the agents out there, but most are lazy and don't hustle to get the deal done. 

I think nothing makes an area come back quicker than it being such a warzone that even the hardened criminals feel the need to move on to have a little security.

You will see citations there that aren't in a criminal record check. 

With the caveat of  not having an ordinance draft in front of me; while we don't accept Section 8 we also have a credit score minimum of 660 and we screen on basis of banking, past landlord(s) and current employment and income (as well as criminal etc).