United States v. Langston was a United States Supreme Court case that dealt with the issue of whether a defendant could be convicted of a crime if the evidence presented at trial was obtained through an illegal search and seizure. The defendant, Langston, was charged with possession of a firearm in violation of the National Firearms Act. The evidence used to convict Langston was obtained through a search of his home that was conducted without a warrant. The Supreme Court held that the evidence obtained through the illegal search and seizure was admissible in court and that Langston could be convicted of the crime. The Court reasoned that the exclusionary rule, which prohibits the use of illegally obtained evidence in court, did not apply in this case because the search was conducted in good faith and the officers had reasonable grounds to believe that the search was lawful. The Court also noted that the exclusionary rule was not intended to be a shield for criminal activity. In conclusion, the Supreme Court held that the evidence obtained through the illegal search and seizure was admissible in court and that Langston could be convicted of the crime. The Court reasoned that the exclusionary rule did not apply in this case because the search was conducted in good faith and the officers had reasonable grounds to believe that the search was lawful.

Justice Field delivered the dissenting opinion in United States v. Langston, arguing that Congress had no authority to pass a law allowing for the sale of public lands within Indian reservations without their consent. He argued that this was an infringement on the rights of Native Americans and violated treaties between them and the U.S., which guaranteed them exclusive possession of these lands until they chose to sell or lease it themselves. Furthermore, he noted that while Congress may have been able to pass such a law if it were necessary for some purpose related to national defense or security, there was no evidence presented in this case showing any such need existed here. As such, Justice Field concluded that Congress' action was unconstitutional and should be overturned by the Court as being beyond its power under Article I Section 8 of the Constitution.