Bankruptcy?

Would a credit bankruptcy hurt your chances of passing the background?

Yes. VERY MUCH SO.

You can have a bankruptcy and pass background but it MUST BE at least 3 to 5 years in your past.
It's much like drug use. As long as it's 5 to 7 years ago, you should have no problem with passing the drug part of a background.
If you did hard drugs (needles, crack, etc.) you will have a REAL problem passing background.
If you have a lot of credit card debt and have carried it for a long time, you will have a problem passing background. If you have paid off all that debt and been in good credit standing for years now - then that's OK.

I know this because my bankruptcy is only a year old and I can't even get an unpaid internship as a Forensic Tech. I've been turned down for the internship and 2 police recruit jobs - -all because of the bankruptcy.

You'll read and be told by background investigators that bankruptcy is not an immediate disqualifier, and it's not, just like drugs are not, but it needs to be a part of your past and 5 years ago is the starting point.