Weeks v. United States

Weeks in 1914 established not only the exclusionary rule, but also an exception to the exclusionary rule called the "Silver Platter Doctrine." This exception covered situations in which federal law-enforcement officers had evidence "handed to them on a silver platter"--Justice Felix Frankfurter's phrase--by state authorities.

The key idea here was the participation of state law-enforcement personnel, who usually worked under less strict requirements regarding search and seizure laws; if federal authorities became involved, the Court ruled in Byars v. United States (1927)--no matter how slight the degree of involvement--improperly obtained evidence would then have to be subjected to the exclusionary rule.

In its application to criminal cases, the Silver Platter Doctrine had a life span of 44 years, until Elkins v. United States (1960). In the meantime, the Court had begun to apply Fourth Amendment principles to the states, and a number of the states themselves had adopted exclusionary rules. But for civil proceedings, the Court held in Janis v. United States (1976), the Silver Platter Doctrine remains valid.