Was there ever a public case in the us were someone thought they had dipolomatic immunity and they didnt?

it was at least 5 years ago but i think i remember the case where there was some lady who was maybe royal somewhere in europe and she was in america and she broke the law somehow an got arrested but freaked out because she said she had diplomatic immunity. i remmeber it being in the news... i think please if anyone could tell me details about this that would be great