It will most likely depend alot on what the nature of the crime was. If it was a violent crime or a crime of sexual nature I can almost gurantee you cannot get the licensing required however if it was a petty misdemeanor crime and it was in your past it's possible.
You should contact the state licensing board in your state and ask them. I once worked with a radiology tech who did his training in prison while he was sentenced for theft. He was fully licensed and was able to go straight once he got out of prison because of the education and training he recieved.
This was years ago though in this day and age a criminal record seems to hold you back even more so than in the past.