An immigration attorney should be consulted regarding the relationship between federal and state law. Generally in Michigan courts, a retail fraud case would be taken under advisement pursuant to MCL 771.1. Under the statute, the file remains public, including the information regarding the entry of the plea. While the law allows the Prosecutor to move for dismissal, the file remains open for anyone to view, including employers and government agents who wish to take the time. So while no conviction is entered, the facts supporting the plea remain available to anyone who asks.
Expungement is a separate procedure. If your conviction qualifies (and it can only be one single count; one conviction) then expungement may be possible. My colleague correctly points out, however, that a deferred sentence does not seal your file from potential employers. The expungement process is explained in an AVVO legal guide posted to my profile. Hope that may assist you.
I would also agree that your next stop needs to be for a consult with an immigration lawyer. Good luck.
A deferred adjudication or a plea taken under advisement with the charges later dismissed, still counts as a "conviction" for immigration law purposes. Therefore, if you plead guilty it will not make any difference for immigration law purposes that the charges were dismissed under state law. You must disclose all arrests and criminal charges on your application for citizenship regardless of whether they resulted in a state law conviction or not. Plus, any arrests or charges will definitely show up on your FBI background check.
You could face deportation depending on the total number of "convictions" you have and the nature of the crimes committed. You can be deported for committing a crime of moral turpitude, and state theft crimes, such as larceny, are generally considered crimes of moral turpitude. You should consult with an attorney before submitting your N-400 to USCIS.
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