¶8. The law appropriately recognizes that sentences may be based on what is unknowingly incomplete information, and, if they are, that there should be some mechanism to correct a resulting injustice. Thus, if after sentencing it turns out that there was something that would have been important to the sentencing court but was either unknown or unknowingly overlooked, the court may resentence the defendant to take the new matter into account. State v. Macemon, 113 Wis. 2d 662, 668, 335 N.W.2d 402, 406 (1983). The hurdle, however, is fairly high: the new factor must be “highly relevant” to the sentence so that its newly revealed existence “frustrates” the court’s sentencing intent. State v. Michels, 150 Wis. 2d 94, 98-99, 441 N.W.2d 278, 280 (Ct. App. 1989). A defendant must prove by “clear and convincing evidence” that what he wants the sentencing court to consider is a “new factor.” State v. Franklin, 148 Wis. 2d 1, 9, 434 N.W.2d 609, 611 (1989).¶9. We review de novo whether something is a new factor. Id., 148 Wis. 2d at 8, 434 N.W.2d at 611. “[W]hether the new factor justifies modification of the sentence” is, however, within the trial court’s discretion. Ibid.