The Supreme Court abandoned the Aguilar–Spinelli test in Illinois v. Gates, 462 U.S. 213 (1983), in favor of a rule that evaluates the reliability of the information under the "totality of the circumstances."
However, Alaska, Hawaii, Massachusetts, New York, Vermont, Oregon, and Washington have retained the Aguilar–Spinelli test, based on their own state constitutions.
In order to obtain a search warrant in the United States, a law officer must appear before a judge or magistrate and swear or affirm that they have probable cause to believe that a crime has been committed.
"[4] In Johnson v. United States, 333 U.S. 10 (1948), the Court said: The point of the Fourth Amendment, which often is not grasped by zealous officers, is not that it denies law enforcement the support of the usual inferences which reasonable men draw from evidence.
Its protection consists in requiring that those inferences be drawn by a neutral and detached magistrate instead of being judged by the officer engaged in the often competitive enterprise of ferreting out crime.