In the United States v. Matlock case of 1973, the Supreme Court ruled that a warrantless search is valid if consent is given by a third party who possesses common authority over or other sufficient relationship to the premises or effects sought to be inspected. The defendant, Jerry Alden Matlock, was arrested at his residence and subsequently indicted for bank robbery. While he was in custody in a squad car nearby but not asked for permission, law enforcement officers obtained voluntary consent from Mrs. Graff (a woman with whom he shared an apartment) to search their shared bedroom where they found money which matched that stolen from the bank. At trial, Mr. Matlock argued this evidence should have been suppressed as it had been obtained through an unconstitutional search since only Mrs.Graff's consent had been secured while he himself hadn't provided any such approval nor was present during her giving of said approval . However,the Supreme Court upheld its admissibility stating that when two people have equal use and control of property then either can give effective consent to its search.

In the dissenting opinion for United States v. Matlock, Justice Douglas argued that the majority's decision to allow a third party to consent to a search of shared premises violated Fourth Amendment rights. He contended that this ruling effectively allowed police officers to bypass obtaining warrants by simply seeking permission from any individual who happened to be present at the time of their arrival, regardless of whether or not they had authority over all areas within those premises. This could lead, he warned, to situations where individuals with minimal connections and little actual control over property could grant law enforcement access without proper authorization from those with legitimate interests in maintaining privacy. Furthermore, Douglas criticized the majority’s reliance on “common authority” as an overly broad concept which failed adequately protect constitutional rights against unreasonable searches and seizures.