Does common law exist in crown court with a plea already in magistrates court on a criminal charge?

Yes, common law principles can apply in Crown Court cases, even if a plea has already been entered in Magistrates' Court. The Crown Court typically handles more serious criminal cases and can consider common law precedents in its rulings. However, the plea entered in the Magistrates' Court may affect the proceedings, as it can lead to issues of double jeopardy or influence sentencing. Ultimately, the Crown Court operates within the framework of statutory law and established legal precedents, including relevant common law.