Procedure for expunging criminal record in WA state

expungement of criminal record: I recently applied for a gun permit, and was declined on the basis of a felony conviction int he State of Missouri, Jackson county. The charge was, if I remember correctly, possession of controlled substances. Thsi was about 1976 or so. I remember the judge, at that time, stating in courst that the charge would be expunged if I stayed out of trouble after that. I have had no toehr problems , except traffic tickets since, but the charge is still on my record. What can I do to get this expunged? - Is this your question? Add additional information