According to FCRA (Fair Credit Reporting Act), you must obtain signed consent from the applicant prior to performing a background check. The FCRA applies to these kinds of reporting activities, in addition to credit reports. Also, state laws differ as to what can be included in a background check, and to how that information can be used in the process of screening applicants. You should check with your attorney, or hire a background screening company with experience in your state, before you start screening employee applications.