First, it depends upon your age when you did the crime. Sometimes, you can get the conviction set aside if you were under a certain age. However, since it was bank robbery, which was prosecuted as a federal offense, its unlikely that you will be able to "expunge" your criminal record.
However, you may wish to hire an attorney who regularly appears in a federal court in your immediate area and ask them if there are any special circumstances under which you can clear such a conviction from your record.
I concur with my collegue. Unfortunately, it is unlikely that you will be able to get this off your record given the type of crime and court of conviction. I also agree that seeking a consultation with an experienced criminal defense lawyer admitted to practice in the District where this occurred would be a good idea. Bring all documentation you have with you to the consult and maybe the lawyer will be able to suggest an alternative course of action. Good luck.
This answer is not intended to, nor does it create, an attorney-client relationship. It is not intended to constitute either legal advice or attorney advertising. Instead, given the nature of this website, it is provided solely for informational purposes, for you to use as a starting point when speaking directly with a lawyer in your State. Do not assume that the legal theories I mention that pertain to NJ will apply in your State. The facts of each case are different, and it is therefore critical for you to consult with a qualified counsel with whom you can share information which can be assessed under an attorney-client privilege, so that you can get competent legal advice from which you can make informed decisions. I urge you to immediately contact an experienced criminal defense lawyer admitted to practice in your State before making any decisions about this case.