In Aguilar v. Texas (1963), the U.S. Supreme Court ruled that an affidavit used to obtain a search warrant must provide sufficient facts to establish probable cause, and cannot simply rely on the belief of law enforcement officers or their confidential informants. The case arose when police in Houston obtained a search warrant based solely on an affidavit stating that they had "reliable information from a credible person" about illegal activity at Manuel Aguilar's residence. During the subsequent search, evidence was found leading to his conviction for possession of heroin. However, Aguilar appealed arguing that there were no specific facts provided in the affidavit supporting probable cause for issuing the warrant as required by Fourth Amendment protections against unreasonable searches and seizures. The Supreme Court agreed with him, ruling 8-1 that such affidavits must contain enough factual information so a neutral magistrate can independently determine if there is probable cause for issuing a search warrant rather than merely accepting assertions made by police officers or their informants.

In the dissenting opinion for Aguilar v. Texas, Justice Clark argued that the majority's decision to overturn a conviction based on an allegedly insufficient affidavit was misguided. He contended that the affidavit in question did provide sufficient basis for a magistrate to issue a search warrant, as it detailed specific criminal activity and named its source of information - an informant who had provided reliable tips in the past. The justice believed that this met constitutional requirements and should have been enough to establish probable cause. Furthermore, he criticized the majority's new standard requiring police officers to include more details about their informants' reliability or personal observations within affidavits, arguing it would unnecessarily burden law enforcement without significantly improving protections against unreasonable searches and seizures.