The Gates decision abandoned the two-pronged test established in Aguilar v. Texas and Spinelli v. United States. The two prongs were a veracity prong, requiring a showing that the informant should be believed, and a basis of knowledge prong, requiring that the tip reveal some of the underlying circumstances from which the informer has concluded that evidence of illegal activity is where the informer says it is. A tip corroborated by the police must be as reliable as one which passes the requirements when standing alone. In the Gates decision, the standard adopted was the 'totality of the circumstances.' The Court felt that this would better achieve the accommodation of public and private interests required by the fourth amendment. The Gates decision loosens the probable cause and reduces the chance that evidence seized following an informer's tip will be excluded from the trial. The Court could have clarified the confusions of the previous decisions instead of taking the far-reaching position it did in Gates. Clarifying the earlier decisions would also have avoided the possible undesirable consequences of the new test. A total of 102 case notes are supplied.