Clearing your criminal police record can be challenging depending on the state where your record is held. In some states, it is automatic. According to Margaret Colgate Love, of The Sentencing Project, all states have some facility to clear at least some of your police record. The federal government only expunges possession of marijuana. Clearing your records can be handled as a pardon, set-aside, expungement or a sealed record.
Contact the county court clerk to find out who handles these requests. Typically it is the authority that hold the records, usually the courts. Follow their instructions, which vary from state to state. A list of each state's handling of police records is available. (See Reference 1.)
Contact your governor's office. You can request a pardon which will exonerate you of your crimes, both misdemeanors and felonies, but this will not expunge or seal your records. Some states require that you get a pardon before you can petition the courts to seal or expunge your records.
Apply for an expungement of your records. This is typically available for arrests, acquittals or other circumstances where the matter is terminated in favor of the accused. This results in the records' being effectively destroyed.
Apply to have your records sealed. This is available for the same circumstances as expungements, but includes convictions. In some states this relates only to misdemeanors, in some states felonies are included, and in others sealing is available only for sentences that have been deferred. In this case, the records are available to law enforcement, the courts and corrections departments, but not to employers or other members of the public.
Apply for a set-aside which results in your conviction being "set aside." In most states this results in a removal of all penalties and disabilities. It does not automatically expunge or seal your record.