I believe EEOC guidelines forbid asking an applicant if they have ever been "arrested"?
This link seems to support that.
Arrests.
As a general rule, employers are not permitted to ask candidates "Have you ever been arrested?" Many arrests do not result in convictions, and inquiries concerning arrests can be perceived as biased against particular minority groups
http://www.sideroad.com/Human_Resour...questions.html
Here the "operative" word is "charged". IMO, this is an illegal question unless the case law bears it out to some degree.
When you are "arrested" you are "charged".