This is a couple of years old, but an invaluable resource regarding the use of credit in background checks.

September 23, 2010 Judy Gootkind, on behalf of the Nation on behalf of the National Association of Professional Background Screeners (NAPBS) testified before the Committee on Financial Services Subcommittee on Financial Institutions & Consumer Credit U.S. House of Representatives on Legislative Hearing on “H.R. 3149, the Equal Employment for All Act”

http://financialservices.house.gov/media/file/hearings/111/gootkind092110.pdf