Is it possible to vacate two “theft 3” charges in Washington?
You can vacate a single misdemeanor conviction once in a lifetime. So, if these were two separate, unrelated charges, you will only be able to vacate the most recent one.
Also, you have to wait three years from the date you completed the last condition of your sentence (paying fines, probation period, etc.). An attorney would be able to analyze whether you qualify to do this yet, and then help you get everything done quickly and correctly. It is possible to do this on your own, but not necessarily easy.