In Davis v. United States (1972), the Supreme Court ruled that a tax evasion conviction did not violate the Fifth Amendment's protection against self-incrimination. The case involved James Earl Davis, who was convicted of evading federal income taxes and argued that he had been compelled to incriminate himself because he was required by law to report his income on tax returns. However, the court held in a 5-4 decision that filing an income tax return is not inherently incriminating; it only becomes so when individuals provide information on illegal activities as part of their reported income. Therefore, requiring citizens to file such returns does not constitute compulsion under the Fifth Amendment. The majority opinion also noted that if taxpayers believe certain disclosures could be self-incriminating, they can raise this issue at the time rather than refusing to file altogether.

In the dissenting opinion for Davis v. United States, Justice William O. Douglas argued that the majority's decision to uphold a conviction based on evidence obtained through an illegal search was in direct violation of Fourth Amendment protections against unreasonable searches and seizures. He contended that by allowing illegally seized evidence to be used in court, the Supreme Court was effectively condoning police misconduct and undermining citizens' constitutional rights. Furthermore, he criticized the "good faith" exception established by the majority as being too vague and subjective, arguing it could easily be manipulated or misinterpreted by law enforcement officials seeking to justify unlawful actions. Ultimately, Douglas believed this ruling set a dangerous precedent that threatened individual liberties and eroded public trust in law enforcement institutions.