In Cowgill v. California (1969), the U.S Supreme Court dealt with a case involving the Fourth Amendment, which protects citizens from unreasonable searches and seizures. The appellant, Mr. Cowgill, was convicted of possessing obscene materials for sale based on evidence obtained through a search warrant issued by a municipal court judge in Los Angeles County. He challenged this conviction arguing that his constitutional rights were violated because there was no probable cause to issue the search warrant as it relied heavily on an affidavit provided by an investigator who had not personally observed any obscenity but rather received information from anonymous sources. The Supreme Court held that even though the informant's reliability or credibility wasn't established prior to issuing the warrant, other corroborating circumstances detailed in the affidavit could provide sufficient basis for finding probable cause under Aguilar v Texas precedent - where it is required that if police rely on informants' tips to obtain warrants they must support their claim with some underlying circumstances indicating its reliability. Thus, despite concerns about potential violations of privacy rights and due process protections against unlawful searches and seizures under Fourth Amendment jurisprudence; in this particular case, given all surrounding facts presented before him at time of issuance; Judge's decision to grant search warrant was deemed constitutionally valid leading upholding Mr.Cowgill’s conviction.

In the dissenting opinion for Cowgill v. California, it was argued that the majority's decision to uphold a state law requiring compulsory retirement at age 70 violated both due process and equal protection clauses of the Fourteenth Amendment. The dissenting justices believed that mandatory retirement laws were not rationally related to any legitimate governmental interest and thus constituted arbitrary discrimination based on age. They contended that such laws unfairly assumed all individuals become unfit for work upon reaching a certain age, ignoring individual differences in health and ability. Furthermore, they asserted these laws deprived older citizens of their right to earn a living without sufficient justification or procedural safeguards, thereby infringing upon their constitutional rights under due process clause. Therefore, they disagreed with the majority's ruling upholding this discriminatory practice.