You have most likely completed a diversion program, and the case was dropped as a result of that. You still have to report it on the citizenship application. Most of the USCIS agents will not care about a small charge like that, but it can technically be used against you, and can make the process a little more difficult. I would highly advise to have the arrest record and any other information expunged. You will still have to report it, but according to the case law, it should not be used against you in a citizenship application if you take these precautions.
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