Ok. So I have a question regarding expungements. Anyone familiar with this please help!!?

My friend caught with petty theft. This is his first and only offense. He had a court date and was sentenced to 1 year probation and a small fine of 100.00 dollars. The probation was completed, and the case was dismissed. Just to make sure everything would be ok for the future, he got an expungement for anything that may be there, he was never fingerprinted for this act. There was also no conviction. This is in Minnesota. Can you tell me if he can still work for the FAA or would this show on a background check? What type of check would it show on if any?? Please and Thank you so much everyone!!! :))