I would not consider a co-signer/guarantor if the primary tenant's income was insufficient or if they had other unfavorable traits that I thought they would be a disaster tenant living in the unit (like a prior eviction, criminal record, etc.) -- co-signers cannot help those things.

In order to avoid any Fair Housing issues, this really should come down to what do your published screening requirements state about a bankruptcy (in addition to credit, income, criminal record, etc)?

You can choose credit only or credit plus criminal & rental history. 

Unless you're not doing a criminal background check.

Unitdash gives a full credit report, criminal history and eviction history for $30.

I ended up paying $3K in fines and now I am having him prosecuted by the NY Attorney General's Office of Financial Fraud.

When I hear squirly info from neighbors of my SEC 8 tenants I start monitoring the court websites to see if any of my 18 year old + occupants have any criminal charges.  

For credit and criminal background checks I've used AmerUSA.com / RealSerious.com (I've found it to be the cheapest)

As a legal analogy, in jury selection, many folks believe what they see on legal TV shows is an accurate representation to our criminal justice system.

(a) A tenant to a residential lease may terminate a lease agreement in the manner provided in this section without penalty or liability, if the tenant or another authorized occupant fears imminent violence after being subjected to:(1) domestic abuse, as that term is defined under section 518B.01, subdivision 2;(2) criminal sexual conduct under sections 609.342 to 609.3451; or(3) stalking, as that term is defined under section 609.749, subdivision 1.