Whether a defendant who did not object to a Rule 11 error must show that the error probably affected his decision to plead guilty in order to obtain relief on plain-error review.
Holding
Yes. A defendant seeking reversal for an unpreserved Rule 11 error must show a reasonable probability that, but for the error, he would not have entered the guilty plea.
Reasoning
Because Dominguez failed to raise the Rule 11 omission in the District Court, Federal Rule of Criminal Procedure 52(b)'s plain-error rule governed. Under that rule, the defendant bears the burden of showing that a plain error affected substantial rights. United States v. Vonn had already established that unpreserved Rule 11 claims receive plain-error review and that an appellate court may examine the entire record, not merely the plea colloquy.
An error affects substantial rights when it has a prejudicial effect on the proceeding's outcome. The Court drew on the prejudice standard used in Strickland and Brady cases: a reasonable probability is one sufficient to undermine confidence in the outcome, not necessarily proof by a preponderance that a different result was more likely than not.
In the guilty-plea setting, the relevant outcome is the defendant's decision to plead. Thus, the necessary causal question is whether the omitted Rule 11 warning reasonably probably would have changed that decision. A single omitted Rule 11 warning is not structural error, so reversal does not follow automatically without a showing of prejudice.
This standard also serves the policies behind plain-error review and plea practice. It encourages timely objections, avoids unnecessary reversals, and respects the finality of guilty pleas, which are central to the functioning of the criminal justice system. The claimed mistake was a violation of a procedural rule, not itself a due-process violation, which further supported requiring a meaningful showing of prejudice.