Our decisions applying the totality-of-the-circumstances analysis outlined above have consistently recognized the value of corroboration of details of an informant's tip by independent police work. In
Jones v. United States,362 U.S. at
362 U. S. 269, we held that an affidavit relying on hearsay "is not to be deemed insufficient on that score so long as a substantial basis for crediting the hearsay is presented." We went on to say that, even in making a warrantless arrest, an officer "may rely upon information received through an informant, rather than upon his direct observations, so long as the informant's statement is reasonably corroborated by other matters within the officer's knowledge."
Ibid. Likewise, we recognized the probative value of corroborative efforts of police officials in
Aguilar -- the source of the "two-pronged test" -- by observing that, if the police had made some effort to corroborate the informant's report at issue, "an entirely different case" would have been presented.
Aguilar, 378 U.S. at
378 U. S. 109, n. 1.
Our decision in
Draper v. United States, 358 U. S. 307 (1959), however, is the classic case on the value of corroborative efforts of police officials. There, an informant named Hereford reported that Draper would arrive in Denver on a train from Chicago on one of two days, and that he would be carrying a quantity of heroin. The informant also supplied a fairly detailed physical description of Draper, and predicted that he would be wearing a light colored raincoat, brown slacks, and black shoes, and would be walking "real fast."
Id. at
358 U. S. 309. Hereford gave no indication of the basis for his information. [
Footnote 12]
On one of the stated dates, police officers observed a man matching this description exit a train arriving from Chicago; his attire and luggage matched Hereford's report, and he was walking rapidly. We explained in
Draper that, by this point in his investigation, the arresting officer "had personally verified every facet of the information given him by Hereford except whether petitioner had accomplished his mission, and had the three ounces of heroin on his person or in his bag. And surely, with every other bit of Hereford's information being thus personally verified, [the officer] had 'reasonable grounds' to believe that the remaining unverified bit of Hereford's information -- that Draper would have the heroin with him -- was likewise true,"
id. at
358 U. S. 313.
The showing of probable cause in the present case was fully as compelling as that in
Draper. Even standing alone, the facts obtained through the independent investigation of Mader and the DEA at least suggested that the Gateses were involved in drug trafficking. In addition to being a popular vacation site, Florida is well known as a source of narcotics and other illegal drugs.
See United States v. Mendenhall, 446 U. S. 544,
446 U. S. 562 (1980) (POWELL, J., concurring in part and concurring in judgment); DEA, Narcotics Intelligence Estimate, The Supply of Drugs to the U.S. Illicit Market From Foreign and Domestic Sources in 1980, pp. 8-9. Lance Gates' flight to West Palm Beach, his brief, overnight stay in a motel, and apparent immediate return north to Chicago in the family car, conveniently awaiting him in West Palm Beach, is as suggestive of a prearranged drug run, as it is of an ordinary vacation trip.
In addition, the judge could rely on the anonymous letter, which had been corroborated in major part by Mader's efforts -- just as had occurred in Draper. [
Footnote 13] The Supreme Court of Illinois reasoned that
Draper involved an informant who had given reliable information on previous occasions, while the honesty and reliability of the anonymous informant in this case were unknown to the Bloomingdale police. While this distinction might be an apt one at the time the Police Department received the anonymous letter, it became far less significant after Mader's independent investigative work occurred. The corroboration of the letter's predictions that the Gateses' car would be in Florida, that Lance Gates would fly to Florida in the next day or so, and that he would drive the car north toward Bloomingdale all indicated, albeit not with certainty, that the informant's other assertions also were true. "b
ecause an informant is right about some things, he is more probably right about other facts," Spinelli, 393 U.S. at 393 U. S. 427 (WHITE, J., concurring) -- including the claim regarding the Gateses' illegal activity. This may well not be the type of "reliability" or "veracity" necessary to satisfy some views of the "veracity prong" of Spinelli, but we think it suffices for the practical, common sense judgment called for in making a probable cause determination. It is enough, for purposes of assessing probable cause, that "[c]orroboration through other sources of information reduced the chances of a reckless or prevaricating tale," thus providing "a substantial basis for crediting the hearsay." Jones v. United States, 362 U.S. at 362 U. S. 269, 362 U. S. 271.
Finally, the anonymous letter contained a range of details relating not just to easily obtained facts and conditions existing at the time of the tip, but to future actions of third parties ordinarily not easily predicted. The letterwriter's accurate information as to the travel plans of each of the Gateses was of a character likely obtained only from the Gateses themselves, or from someone familiar with their not entirely ordinary travel plans. If the informant had access to accurate information of this type a magistrate could properly conclude that it was not unlikely that he also had access to reliable information of the Gateses' alleged illegal activities. [Footnote 14] Of course, the Gateses' travel plans might have been learned from a talkative neighbor or travel agent; under the "two-pronged test" developed from Spinelli, the character of the details in the anonymous letter might well not permit a sufficiently clear inference regarding the letterwriter's "basis of knowledge." But, as discussed previously, supra, at 462 U. S. 235, probable cause does not demand the certainty we associate with formal trials. It is enough that there was a fair probability that the writer of the anonymous letter had obtained his entire story either from the Gateses or someone they trusted. And corroboration of major portions of the letter's predictions provides just this probability. It is apparent, therefore, that the judge issuing the warrant had a "substantial basis for . . . conclud[ing]" that probable cause to search the Gateses' home and car existed. The judgment of the Supreme Court of Illinois therefore must be
Reversed.
.]
, reversing prior Wisconsin cases which held that a search warrant could not properly issue on the basis of hearsay evidence.
) :
