It was applied in 1955 in California supreme court in a case between people V. Cahan, so by almost 1960, 22 sates in USA adopted the rule, this are califormia, Delaware, Frorida, Idaho, Illinois, Indiana, Kentucky, Mississippi, Missouri, Montana, north, Caolina, Oldahoma, Oregon, Rhode Island, Tennesse, Washington, Texas, west Vigina, Wisconsin, Wyoming, Michigan.
Also Exclusionary Rule does not bar the introduction of all evidence obtained in violation of the fourth, Fofth, or Sixth Amendment in case of Criminal case. See Hudson V. Michigan, 547. U.S. 586, 126 S. Ct. 2159 (june 1, 2006), justice scalia write for U.S. Supreme court.
(http://en.wikipedia.org/wiki/Exclusionary_rule)Suppression of evidence, however, has always been our last resort, not our first impulse. The exclusionary rule generates "substantial social costs," United States v. Leon, 468 U.S. 897, 907 (1984), which sometimes include setting the guilty free and the dangerous at large. We have therefore been "cautious against expanding" it, Colorado v. Connelly, 479 U.S. 157, 166 (1986), and "have repeatedly emphasized that the rule's 'costly toll' upon truth-seeking and law enforcement objectives presents a high obstacle for those urging [its] application," Pennsylvania Bd. of Probation and Parole v. Scott, 524 U.S. 357, 364-365 (1998) (citation omitted).