Ouch...gotta read those things carefully!
I had a similar thing happen to me...not totally of my own fault. One of my letter writers (a pathologist) wrote in his LoR that I would make a great pathologist. However, I was applying to Derm! He knew I was between path and derm, but I guess it wasn't conveyed that my final decision was Dermatology or maybe it was and he didn't remember it when he was writing the letter. He's a big name in Pathology, so I know he is a busy person, so I understand how it would happen.
I had of course waived my right to read the letter so it was submitted to all 85 Derm programs to which I applied. When I met with him again, we talked about dermatology and my application and we figured out the mistake. He contacted the med school office and he changed the letter immediately, but it had already been downloaded by almost all the programs to which I applied.
In the meantime I individually emailed all the program coordinators (all 85) and explained the situation/mistake. That took the better half of a Friday afternoon/evening. heh
Most know how bad it can look applying to multiple specialties, so I was worried. However, I ended up with 20 IIs so I don't think it affected me too much.
In your situation, I wouldn't think a background check would be necessary since you shouldn't have any felonies on your record. However, it may be a good idea to get the result of the search and send a copy to all the schools to which you applied.
Here is some information to get you started:
http://travel.state.gov/content/passports/en/abroad/legal-matters/criminal-record-check.html
