Rule 615 - The Cause on Appeal(a) Insubstantial and Substantial Errors on Appeal. Any error, defect, irregularity, or variance which does not affect substantial rights shall be disregarded. Plain errors or defects affecting substantial rights may be noticed although they were not brought to the attention of the trial court.(b) Powers of the Reviewing Court. On appeal the reviewing court may: (1) reverse, affirm, or modify the judgment or order from which the appeal is taken;(2) set aside, affirm, or modify any or all of the proceedings subsequent to or dependent upon the judgment or order from which the appeal is taken;(3) reduce the degree of the offense of which the appellant was convicted;(4) reduce the punishment imposed by the trial court; or Committee Comments
This is section 121 -- 9 of the Code of Criminal Procedure of 1963 without change in substance.
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