Appellant was charged with driving under the influence, with three prior convictions, which elevated the current offense to a felony. He filed a motion to strike the prior convictions, claiming that they were constitutionally invalid because the record in those cases did not reflect a waiver of his constitutional right to a certified court interpreter. The trial court granted the motion, and the prosecutor filed a petition for writ of mandate. The appellate court here granted the prosecutor’s petition. Although appellant had a constitutional right to a court interpreter, the constitution makes no requirement that the interpreter be certified. California Rules of Court, rule 984.2 provides detailed procedures for the use of a noncertified interpreter. The mere failure to follow its requirements, however, does not necessarily violate a defendant’s constitutional rights unless it results in prejudice. Here, there was no claim that the interpreter was not competent, nor did appellant demonstrate that he did not understand the proceedings. Therefore, there was no constitutional violation.