Fair Housing Law thoughts

[Peter K.]

So I want to be sure I am not in violation of the Fair Housing Law so wanted to pose a question:

I am in the middle of conducting my pre-screening application for potential tenants, I denied someone who did not meet the requirements (this individual - lets name him GARY- his credit score was not 600+ and this individual was not a student). I have another person-lets name him JOHN- that does not meet the x3 income and does not have 600+ credit score BUT he is a student. If he agrees to a co-signed/extra security deposit and I sign him on the lease will I be violating the Fair housing law? Hypothetically, GARY could have had a co-signer/extra security deposit even though he did not meet the requirement(s) but I denied him due to his score. Any thoughts?