§ 320.10.  Non-jury trial; when authorized
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2. Such waiver must be in writing and must be signed by the defendant in person in open court in the presence of the court, and with the approval of the court. The court must approve the execution and submission of such waiver unless it determines that it is tendered as a stratagem to procure an otherwise impermissible procedural advantage or that the defendant is not fully aware of the consequences of the choice he is making. If the court disapproves the waiver, it must state upon the record its reasons for such disapproval.