I've got one of those badges for working under the capitol building in the new visitors center. I got my badge at E st and South Capitol st in south west. Finger print, retnal scan... Alot of people I work with have messy pasts, and they're getting on site no problem, so I wouldn't be to worried, especially if the company you're applying through is a respectable place.

**edit**
by messy I meant federal records, not messenger...