PART II
Procedure in Criminal Actions
Chapter 16. ARRAIGNMENT, PLEAS, AND PRETRIAL MOTIONS
ยง16.5. Arraignment, judgment, and sentence after plea of guilty.
If a defendant after indictment desires to enter a plea of guilty, he shall be arraigned immediately in open court even though the court is not then in session. If this plea is accepted, sentence shall be imposed without delay, or immediately on the receipt of a presentence report if such a report is required by law or requested by the judge. No trial is necessary following a plea of guilty. A sentence imposed in chambers after a plea of guilty shall have the same force and effect as though in open court. The clerk shall record the judgment and enter sentence in the manner provided for judgments and sentences pronounced in open court.
National proceedings on admission of guilt
EDIT.