Bad credit is lower on the list for the qualification process.  Criminal record, employment, and rent history are in most cases more important.  For people that lack all or a few of qualifying criteria there are always places that don't do not do proper screening.  Also larger units tends to be more relaxed (not always). 

As mentioned, they rent from places that don't screen.  Or, they rent from places that might take them with a larger security deposit.

Gail

There are LOTS of landlords that do not run credit checks. Sounds crazy to most of us, but they just don't know any better. 

Depends on what makes up the bad credit.

If someone filed a chapter 7 and wiped out tons of debt it could be a good thing as they now have little debt and can pay the rent easier.

Also someone could have short sold their house or did a foreclosure because they could no longer afford the house and it was upside down in value. They are now wanting to downsize to a rental they can afford.

The bad credit could also be medical bills. Medical bills owed generally are not treated with the same weight as other collections. People get a life health issue and it takes awhile to bounce back.

So when you analyze credit you have to see what makes up the bad credit that will make them a bad tenant for you.