Answer:
a criminal trial involving a U.S ambassador
Step-by-step explanation:
Under federal law at 28 U.S.C, the Supreme Court would be the first to hear and handle a criminal trial involving a U.S ambassador. This is because the Supreme Court has original and exclusive jurisdiction over all extremely important cases that involve any problems between the states and/or any trial which involves U.S ambassadors or public ministers, even though these cases are rare and unique.