In the case of Irizarry v. United States (2007), the U.S. Supreme Court ruled that a judge is not required to inform a defendant about his intention to impose a sentence that deviates from federal guidelines before it happens, even if this deviation comes as a surprise to the defendant. The decision was based on an appeal by Alejandro Irizarry who had pleaded guilty to threatening his ex-wife but received an unexpectedly harsh sentence due to additional factors considered by the judge during sentencing. The court held that since these federal guidelines were advisory rather than mandatory, there was no obligation for advance notice of any departures from them.

In the dissenting opinion for Irizarry v. United States, Justice Breyer argued that a defendant should be given notice when a judge is considering an upward departure from the sentencing guidelines range. He believed this was important to ensure fairness and allow defendants adequate time to prepare their arguments against such departures. The majority's decision, he contended, would lead to unfair surprise and could undermine confidence in the justice system by making sentences appear arbitrary or capricious. Furthermore, he pointed out that providing notice does not impose significant burdens on courts or prosecutors while offering substantial benefits in terms of fairness and accuracy in sentencing decisions.