Minn. Stat. § 631.20: HEARING; SENTENCE.

After a plea or verdict of guilty, if the court has discretion as to the extent of the punishment, and if either party suggests that there are aggravating or mitigating circumstances which may be properly considered in imposing sentence, the court may hear the issue summarily, at a specified time, and upon notice to the adverse party as it may direct. The aggravating or mitigating circumstances must be presented by the testimony of witnesses examined in open court.