In the case of Justices of Boston Municipal Court v. Lydon, the U.S Supreme Court was tasked with determining whether a defendant who had been acquitted in a bench trial could be retried by jury without violating his Fifth Amendment right against double jeopardy. The defendant, Lydon, had chosen to have a two-tier system for his misdemeanor charge which involved an initial bench trial followed by de novo jury trial if he was dissatisfied with the first verdict. After being found guilty at the bench trial but acquitted at de novo jury review on one count and convicted on another count, he sought to prevent further prosecution arguing it would constitute double jeopardy. The court ruled 5-4 that retrying Lydon did not violate his rights under the Double Jeopardy Clause because he voluntarily chose this two-tiered system knowing fully well that either party could appeal after an initial non-jury conviction or acquittal. Therefore, since both trials were part of one continuous proceeding rather than separate ones and given that Massachusetts law allowed such proceedings as long as they were initiated by defendants themselves; there was no violation of constitutional protections against double jeopardy.

In the dissenting opinion for Justices of Boston Municipal Court v. Lydon, Justice Brennan disagreed with the majority's interpretation of double jeopardy protections. He argued that a defendant who is acquitted in a bench trial should not be subjected to another trial by jury on the same charges, as this violates their Fifth Amendment rights against being tried twice for the same offense. In his view, an acquittal at any stage should terminate all proceedings related to that charge and protect defendants from government oppression through repeated prosecutions. The majority’s decision allowing retrial after an initial non-jury acquittal undermines these protections and fails to respect judicial finality.