In Gori v. United States, the Supreme Court examined whether a trial judge could declare a mistrial without the defendant's consent and if this would violate their protection against double jeopardy. The case arose when Joseph Gori was on trial for narcotics charges and his attorney made an inappropriate statement to the jury about evidence that had been excluded from the proceedings. The judge declared a mistrial out of concern that this comment might unfairly influence the jury in favor of Gori, even though neither party requested it nor did they object at that time. The Supreme Court ruled 5-4 in favor of upholding Gori’s conviction upon retrial, stating that judges have discretion to declare mistrials under circumstances where there is "manifest necessity" or "the ends of public justice would otherwise be defeated." They found no violation of double jeopardy protections as these are not absolute but must accommodate other important interests such as ensuring fair trials. This decision affirmed judicial authority to protect integrity and fairness within court proceedings by declaring mistrials when necessary.

In the dissenting opinion for Gori v. United States, Justice Hugo Black argued that the majority's decision violated the defendant's constitutional right to a fair trial by jury. He contended that it was unconstitutional for a judge to declare a mistrial and force a new trial without obtaining consent from the defendant unless there were "manifest necessity" or an urgent situation requiring such action. In this case, he believed no such urgency existed; instead, it seemed like an attempt by prosecution to secure more favorable conditions in another trial after realizing their evidence might not be sufficient enough for conviction in current one. This practice of declaring mistrials at will could lead to abuse where prosecutors would use trials as mere dress rehearsals until they get everything perfect according to them which is against principles of justice and fairness enshrined in Constitution.