In Robert Kaupp v. Texas, the U.S. Supreme Court ruled in favor of Robert Kaupp, who was convicted for murder based on a confession he made during an unlawful arrest. The police had no probable cause or warrant when they arrested him at his home and took him to the crime scene where he confessed to involvement in a murder case after being shown evidence against his brother. The court held that this violated the Fourth Amendment's protection against unreasonable seizures because there was no probable cause for arrest nor consent given by Kaupp before entering his home and taking him into custody. Therefore, any subsequent statements made by Kaupp were deemed as fruits of an illegal seizure and should have been suppressed from use at trial under the exclusionary rule which prohibits introduction of evidence obtained through violation of defendant’s constitutional rights.

In the dissenting opinion for Robert Kaupp v. Texas, it was argued that the majority's decision to suppress Kaupp's confession due to an illegal arrest was incorrect. The dissenters believed that there wasn't a sufficient causal connection between the unlawful police conduct and Kaupp’s subsequent incriminating statements at the station house. They pointed out that his confession came after he had been read his Miranda rights, which should have broken any link with earlier misconduct by law enforcement officers. Furthermore, they noted that even if there were some tenuous connection between these events, it would not be enough to trigger suppression under existing precedents of Fourth Amendment jurisprudence.