The bottom line is that once the paperwork gets started in a case, it can only be disposed of by a judge. If you do not go to court to make sure it gets taken care of, then you run the risk of getting a charge of "failing to appear" to go with the show cause. As to whether you need an attorney - it depends on whether you have the appropriate paperwork to prove that you weren't convicted and feel comfortable in front of the judge to present it.
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