The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.
Requirements for establishing probable cause through reliance on information received from an informant has divided the Court in several cases. Although involving a warrantless arrest, Draper v. United States1 may be said to have begun the line of cases. A previously reliable, named informant reported to an officer that the defendant would arrive with narcotics on a particular train, and described the clothes he would be wearing and the bag he would be carrying; the informant, however, gave no basis for his information. FBI agents met the train, observed that the defendant fully fit the description, and arrested him. The Court held that the corroboration of part of the informer’s tip established probable cause to support the arrest. A case involving a search warrant, Jones v. United States,2 apparently considered the affidavit as a whole to see whether the tip plus the corroborating information provided a substantial basis for finding probable cause, but the affidavit also set forth the reliability of the informer and sufficient detail to indicate that the tip was based on the informant’s personal observation. Aguilar v. Texas3 held insufficient an affidavit that merely asserted that the police had
reliable information from a credible person that narcotics were in a certain place, and held that when the affiant relies on an informant’s tip he must present two types of evidence to the magistrate. First, the affidavit must indicate the informant’s basis of knowledge – the circumstances from which the informant concluded that evidence was present or that crimes had been committed – and, second, the affiant must present information that would permit the magistrate to decide whether or not the informant was trustworthy. Then, in Spinelli v. United States,4 the Court applied Aguilar in a situation in which the affidavit contained both an informant’s tip and police information of a corroborating nature.
The Court rejected the
totality test derived from Jones and held that the informant’s tip and the corroborating evidence must be separately considered. The tip was rejected because the affidavit contained neither any information which showed the basis of the tip nor any information which showed the informant’s credibility. The corroborating evidence was rejected as insufficient because it did not establish any element of criminality but merely related to details which were innocent in themselves. No additional corroborating weight was due as a result of the bald police assertion that defendant was a known gambler, although the tip related to gambling. Returning to the totality test, however, the Court in United States v. Harris5 approved a warrant issued largely on an informer’s tip that over a two-year period he had purchased illegal whiskey from the defendant at the defendant’s residence, most recently within two weeks of the tip. The affidavit contained rather detailed information about the concealment of the whiskey, and asserted that the informer was a
prudent person, that defendant had a reputation as a bootlegger, that other persons had supplied similar information about him, and that he had been found in control of illegal whiskey within the previous four years. The Court determined that the detailed nature of the tip, the personal observation thus revealed, and the fact that the informer had admitted to criminal behavior by his purchase of whiskey were sufficient to enable the magistrate to find him reliable, and that the supporting evidence, including defendant’s reputation, could supplement this determination.
The Court expressly abandoned the two-part Aguilar-Spinelli test and returned to the
totality of the circumstances approach to evaluate probable cause based on an informant’s tip in Illinois v. Gates.6 The main defect of the two-part test, Justice Rehnquist concluded for the Court, was in treating an informant’s reliability and his basis for knowledge as independent requirements. Instead,
a deficiency in one may be compensated for, in determining the overall reliability of a tip, by a strong showing as to the other, or by some other indicia of reliability.7 In evaluating probable cause,
[t]he task of the issuing magistrate is simply to make a practical, commonsense decision whether, given all the circumstances set forth in the affidavit before him, including the ‘veracity’ and ‘basis of knowledge’ of persons supplying hearsay information, there is a fair probability that contraband or evidence of a crime will be found in a particular place.8