(Obviously aside from the renter voluntarily tells you that they had bankruptcy, unpaid bills etc.)

Have you ever been evicted, have you filed bankruptcy, do you smoke, how much do you make, etc. 

You can require a credit score of 700+, income 3 times the rent, no criminal history - at all, no evictions, no bankruptcies, excellent landlord references for the past 3 years, proof of steady income for the last year. 

A person with an unfavorable credit history, like a bankruptcy, but no other negative indicators, who applies for an apartment.

I haven't invested in Vallejo for quite some time and it is one of the few cities in CA that claimed bankruptcy during the downturn.  

Any bankruptcies, collections, late payments, judgments etc?

@Glen Smith I think you should talk to a bankruptcy attorney. 

Don't invest with your sister.Look for for sale by owner properties.You might want to consider bankruptcy. 

I just rented a house to a couple that in 2014 filed for bankruptcy.

He had already filed for bankruptcy and abandoned the home.I remember I was very nervous until I got the abstract of title back, wondering if there were any junior lien holders.