In the case of Mario Salinas v. United States in 1997, the Supreme Court ruled that a defendant's silence during informal questioning by police can be used as evidence of guilt at trial if he did not expressly invoke his Fifth Amendment right to remain silent. The case involved Mario Salinas who was convicted for murder in Texas and sentenced to 20 years imprisonment. During an informal interview with police before being arrested or read his Miranda rights, Salinas answered all questions but remained silent when asked whether shotgun shells found at the crime scene would match a gun found at his home. At trial, prosecutors argued this silence indicated guilt which contributed to his conviction. On appeal, Salinas argued that using his pre-arrest silence against him violated the Fifth Amendment’s protection against self-incrimination; however, the Supreme Court disagreed stating that unless a suspect explicitly invokes their right to remain silent it does not apply during voluntary discussions with authorities.

In the dissenting opinion for Mario Salinas v. United States, it was argued that the majority's decision to uphold Salinas' conviction on a federal firearms charge undermined the principle of dual sovereignty in American law. The dissent contended that by allowing federal prosecution following state acquittal, this ruling effectively permitted double jeopardy - trying an individual twice for the same crime - which is prohibited under the Fifth Amendment. They also expressed concern over potential abuse of power by prosecutors who could use this loophole to retry defendants they were dissatisfied with at a state level in federal court. Furthermore, they believed that such decisions should be left up to Congress rather than being judicially determined and criticized what they saw as an overly broad interpretation of Congressional intent regarding gun control laws.