Friday, 23 December 2016 04:56

Search Engine Evidence and the 'Aguilar-Spinelli' Test


New technologies inspire clever criminals, requiring more advanced law enforcement crime fighting methodologies. This "circle of life" inevitably includes post-arrest motions questioning the existence of "probable cause" to arrest and/or search1 by criminal defense attorneys duty-bound to zealously defend their clients. Their arguments usually include the application of long-established legal rules to challenge these new government investigative methodologies. One such rule is the so-called Aguilar-Spinelli test, which has been asserted in an attempt to undermine search engine evidence used in search warrant applications.

'Aguilar-Spinelli' Test

In Aguilar v. Texas, 378 U.S. 108 (1964), a local Texas judge issued a warrant to search for narcotics in defendant's home based on an affidavits filed by two city police officers reciting that they were based on reliable information from a credible person that narcotics were being kept at defendant's premises for illegal sale and use. The affidavit provided no further information concerning either the undisclosed informant or the reliability of the information. The warrant was issued, a search was conducted, and the narcotics evidence was seized and later admitted at the trial, at which defendant was found guilty of possessing heroin. The U.S. Supreme Court reversed the conviction, finding the warrant defective as the affidavit in support was inadequate for two reasons: First, the application failed to set forth any of the underlying circumstances necessary to enable the issuing justice to independently assess the informant's conclusion that the narcotics were where he said they were (first prong of the test); and second, that the affiant-officers did not support their claim that their informant was credible or his information reliable (the second prong of the test).

About five years later, in Spinelli v. United States, 393 U.S. 410 (1969), the defendant was convicted of illegal interstate gambling activities and challenged the constitutionality of the warrant that authorized the FBI search. The warrant was granted by a federal magistrate judge on the affidavit of an FBI agent who attested to certain FBI surveillance of defendant's travels to and from an apartment, a review of telephone records showing two phones in someone else's name at the apartment, and information from a confidential reliable informant who had informed the authorities that defendant was known to be operating a gambling operation. On certiorari, the Supreme Court found the warrant defective under the Fourth Amendment because it failed to set forth the underlying circumstances necessary to enable the judge to independently assess the Confidential Informant's (CI's) information (first prong of test) and the affiant-officers failed to support their claim that their informant was "credible" or his information "reliable" (second prong). Furthermore, on the issue of the FBI's corroboration of the CI, the Supreme Court determined that the CI's information was not sufficiently enhanced by the FBI's corroboration of certain limited aspects of the informant's report—that Spinelli traveled to an apartment that had two phones listed to it in another's name—because that information did not independently suggest criminal conduct. The information was equivocal and not considered abnormal activity. The court clarified how the affidavit was defective and could have been remedied: The affidavit did not say how the CI got his information; it did not say if the CI had observed Spinelli taking bets; it did not say whether the CI had ever placed bets with Spinelli; or whether the CI got the information firsthand or from a reliable third party.

The High Court in Spinelli also found that in the absence of a statement of how the CI got his information, it was important to describe the accused's criminal conduct in sufficient detail so that the issuing judge would know that he was relying upon more than rumor or general bad reputation information.

Further, the bald assertion in the affidavit that defendant was "known" as a gambler was entitled to no weight in reviewing the magistrate's decision. The court rejected as imprecise the "totality of circumstances" approach embraced by the lower court. Thus, the affidavit fell short of providing probable cause as necessary to support the issuance of the search warrant under the Fourth Amendment.

Although later abandoned by the Supreme Court, the Aguilar-Spinelli test has been retained by New York as a matter of state constitutional law, and continues to be used to determine the constitutional requirement of probable cause when hearsay evidence from an undisclosed informant is utilized in a search warrant affidavit or as the basis of a warrantless arrest. See People v. Elwell, 50 N.Y.2d 231 (N.Y. 1980). Hearsay from an undisclosed informant forming some basis of an application for a search warrant must be sufficient to establish the basis of knowledge of the informant's information and the veracity of the informant. The protection provided these two components differs and each must be analyzed independently and evaluated separately.2 The purpose of the basis of knowledge inquiry is to assure that the informant's tip does not reflect inaccurate information or rumor, and requires at least some details in the informant's statement be of criminal activities showing that the source had firsthand knowledge of the criminal endeavor. The second prong—the veracity of the informant prong—must demonstrate the trustworthiness or reliability of the informant.

At times it can be confusing because some courts refer to informants generically in their decisions categorizing informants based upon their status. For instance, the test does not apply to a named informant disclosed to the court with personal knowledge of the facts asserted because a named informant may be prosecuted for false reporting, and a named citizen informant's reliability under the second prong of the test is presumed, unless there is materially impeaching evidence.3

Search Engine Informants

More recently, in People v. Pierre, 51 Misc.3d 1035 (Kings County 2016), defendant moved to controvert the search warrant that had been executed on a computer in his residence, which resulted in the seizure of child pornography. Part of the basis for the probable cause for the warrant was information obtained via subpoenas from the Internet search engine, Google. Proprietary software used by Google assisted in confirming that material evidence of child sexual abuse may be found on the subject computer through a process of "digital fingerprinting," that is, matching a hash value to a known value for an image of child pornography. This information was later confirmed by follow-up through human examination. Id. at 1037, n.3.

In Pierre, defendant contended that the information supplied to the issuing judge by the law enforcement affiant, based in part from Google, failed to establish the reliability and basis of knowledge of the informant (that is, Google) per the Aguilar-Spinelli test. Thus, the affidavit failed to satisfy the probable cause standard required by the Fourth Amendment for the search. The defense argued that the government's reliance upon Google's report of the child pornography in question, was analogous to reliance upon a confidential informant and required adherence to the rigid two-prong Aguilar-Spinelli test.

The court in Pierre rejected the defense contention that the test was applicable, relying in part on the absence of federal case law, although acknowledging that the federal courts no longer follow the Aguilar-Spinelli test. The test was abandoned in Illinois v. Gates, 462 U.S. 213 (1983), where the Supreme Court determined that as a matter of federal constitutional law the less stringent "totality of circumstances" standard was sufficient for search warrant applications based on hearsay from an undisclosed informant. Under the Gates standard, the issuing court need only make a practical, common-sense decision whether, given all the circumstances set forth in the affidavit for the search warrant, including the veracity and basis of knowledge of persons supplying hearsay information, there is a fair probability that the evidence sought will be located at the place to be searched. The test was further diluted under federal law when, in United States v. Leon, 468 U.S. 897 (1984), the High Court adopted a "good faith" exception to the warrant requirement and denied suppression of evidence seized pursuant to a defective search warrant on the ground that the police acted in objectively reasonable good faith and in the objectively reasonable belief that probable cause existed.

States are free, of course, as a matter of state constitutional law to impose greater restrictions on police activity than those imposed by the Supreme Court as a matter of federal constitutional law. A state may decide to provide greater protections, and, accordingly today New York is only one of five states that has retained the Aguilar-Spinelli test providing its citizens with greater protections.4

One avenue the courts have found to establish an informant's basis of knowledge in the absence of a clear statement by the informant of the source of his information has been through subsequent police verification of the details of the tip itself prior to making an arrest.5 In Pierre, it was noted that the hash file information supplied by Google was confirmed by human examination. A manual human review to confirm the image contained child pornography was conducted by a Google employee who matched the hash value to the child pornography file value. Further, information was supplied to law enforcement by Google in response to a subpoena, and duly authenticated by a Google employee authorized to issue certifications of corporate records. This methodology would place the information outside the rigors of the Aguilar-Spinelli test applicable to undisclosed informants. The informer, Google, was named, the information involving the defendant in criminal activity was set out in detail through hash value review by a corporate employee, as was the means by which the informant acquired the information. Additionally, although the court in Pierre acknowledged that the U.S. Department of Justice Guidelines Regarding the Use of Confidential Informants (§1(B)(6) (January 2001)) defined a confidential informant broadly as any individual who provides useful and credible information to a Department of Justice law enforcement agency regarding felonious criminal activities, it declined to adopt defendant's characterization of Google as a confidential informant and the application of the Aguilar-Spinelli test in light of there being no relevant case law to support it. The court in Pierre found that the federal district courts that had reviewed search warrants with search engine evidence included in the applications thereof were unanimous in their tacit acceptance of the reports made by the Internet search engines. The reliability of the information reported or the basis of knowledge of the reporter was never found questioned.

The basis of knowledge analysis in People v. Hicks, 38 N.Y.2d 90, 92-94 (N.Y. 1975) is particularly instructive. There, the N.Y. Court of Appeals stated:

The informer related criminal activity that he had personally observed and heard on the premises in question. The information furnished was not based upon casual rumor, surmise, suspicion or general reputation … the Magistrate could have reasonably believed that [the defendant] had committed criminal acts, the fruits of which were openly stored in and about his residence . … The sworn statements of private citizens, who report crime in an honest and forthright manner, may, and should be relied upon by the police and the courts as a basis for further action. It is not uncommon to place such heavy reliance upon the role of citizen informers.

The Pierre case stands in stark contrast to cases in which the courts have determined that an informant had no basis of knowledge. For instance, in People v. Smith, 135 A.D.2d 190 (2d Dept. 1988), airline personnel were suspicious of a package and called police who searched it without a warrant on the belief that it might contain explosives. The package did not contain explosives, instead it contained cocaine. The court invalidated the search, finding there was no basis for the airline personnel's suspicions that the package contained explosives, as an x-ray of it had revealed nothing metallic and nothing that appeared to be a detonator, and the bomb squad was never notified. In Pierre, by contrast, there was the undoubted identification of child pornography by Google established by hash mark examination and human follow-up.


It is expected that the criminal defense bar will argue for the application of long-established rules of law to evolving technology employed by law enforcement to combat new criminal endeavors. The arguments for and against the application of the Aguilar-Spinelli constitutional test to search engine evidence demonstrate one of the challenges the courts face in applying an established legal rule to advanced law enforcement investigative methodology, and the discussion above illustrates how the issue was analyzed and resolved in certain cases.


1. The Fourth Amendment provides, in pertinent part, that "… no Warrants shall issue, but upon probable cause …" and applies, of course, to arrest warrants, search warrants and eavesdropping warrants. See Aguilar v. Texas, 378 U.S. 108, 111 (1964). See also Berger v. New York, 388 U.S. 41, 55 (1967) for a definition of probable cause.

2. See People v. DiFalco, 80 N.Y.2d 693 (N.Y. 1993)People v. Voner, 74 A.D.3d 1371 (2d Dept. 2010).

3. See People v. Taylor, 73 N.Y.2d 683 (N.Y. 1989)People v. McCulloch, 226 A.D.2d 848 (3d Dept. 1996), lv. den. 88 N.Y.2d 1070 (N.Y. 1996); People v. Chip, 75 N.Y.2d 327, 339-40, cert. den. 498 U.S. 883 (1990); People v. Read, 74 A.D.3d 1245, 1246 (2d Dept. 2010).

4. See Oregon v. Haas, 420 U.S. 714 (N.Y. 1975)People v. Bigelow, 66 N.Y.2d 417 (N.Y. 1985) (rejects the "totality of circumstances" standard and good faith exception to the warrant requirement); People v. Griminger, 71 N.Y. 2d 635 (N.Y. 1988) (reaffirms its rejection of the totality of circumstances standard).

5. See People v. Rodriguez, 52 N.Y.2d at 492; People v. Elwell, 50 N.Y.2d 231 (N.Y. 1980)People v. Stewart, 176 A.D.2d 1098 (3d Dept. 1991).

Author : Peter A. Crusco

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