At issue in this case are several claims of error regarding the issuance of a search warrant, which include the sufficiency and reliability of an affidavit containing multiple layers of hearsay as a basis for the search warrant. The district court rejected the defendant’s arguments, including that the warrant improperly relied upon unreliable and stale hearsay, and found instead that the magistrate had a substantial basis to find probable cause to issue a warrant to search the defendant’s residence. We take the district court’s position on the issues and, exercising jurisdiction pursuant to 28 U.S.C. § 1291, affirm.
I
On March 9, 2001, a warrant was executed at defendant Douglas Mathis’s residence authorizing a search for records and other evidence of his purported illegal ac *1203 tivities, including distribution of methamphetamine and possession of stolen vehicles. During the execution of the warrant, law enforcement agents observed Mathis run out the back door of the residence and drop a small pouch from his hand; authorities also found drug paraphernalia at the residence. Robert Walden, an investigator for the District Attorney and the affiant for the first search warrant, then requested a second warrant to search Mathis’s residence for evidence of possession and distribution of methamphetamine. The second warrant was executed the same day and, as a result of evidence obtained under these warrants, Mathis was arrested.
Mathis was indicted June 13, 2002 by a federal grand jury; the three count indictment charged him with drug and firearms violations, including the manufacture, distribution, and use of methamphetamine. Mathis moved to suppress the- evidence obtained pursuant to the two warrants, alleging that the information upon which the magistrate judge relied in issuing the first warrant was stale and based on impermissible hearsay and, therefore, that the warrant issued without probable cause.
Specifically, Mathis alleged that the probable cause supporting the first search warrant rested almost entirely upon information from four confidential cooperating witnesses (CW # 1-4). According to Mathis, the information provided by those cooperating witnesses was stale, inconsistent, and filtered through an unknown number of law enforcement agents before reaching the affiant, Walden. As a result, Mathis claimed the magistrate who issued the warrants had no substantial basis upon which to accept the cooperating witnesses’ information, and without such a basis, the first search warrant lacked probable cause. Because the first search warrant was not based on probable cause, Mathis continued, any evidence obtained under the second warrant whs tainted and must also be suppressed.
After filing' the motion to suppress, Mathis also filed a motion to compel disclosure of the identity of the confidential informants who provided information to Walden. The district court held hearings on both motions and conducted an in camera inspection of documents which revealed the identities of the informants’ at issue. When the court denied both motions, Mathis conditionally pled guilty to Count Two of the indictment, possession with intent to distribute methamphetamine. He was sentenced to ninety-six months in prison, followed by forty-eight months of supervised release. Mathis appeals to this court, arguing that the district court erred both in denying his motion to suppress the evidence and in denying his motion to reveal the identities of the confidential informants.
II
We consider: (1) whether the first search warrant lacked probable cause due to hearsay and staleness problems such that all evidence obtained under either search warrant should be suppressed,
see Wong Sun v. United States,
A
The United States Constitution requires that “no Warrants shall issue, but upon probable cause, supported by Oath or affirmation.” U.S. Const., amend IV. While the phrase “probable cause” is not self-
*1204
defining, the Supreme Court has described the probable cause inquiry as a “commonsense, practical question” to be informed by the totality of the circumstances present in any particular case.
Illinois v. Gates,
Mathis initially argues that the first search warrant lacked probable cause because the affidavit underlying the search warrant was based upon unknown layers of hearsay. The problem, Mathis contends, is that Walden did not receive the information he described in the affidavit from the cooperating witnesses directly; rather, each cooperating witness related his or her tale to other law enforcement agents who then passed along the information to Walden. Mathis claims the magistrate’s reliance on Walden’s testimony regarding information relayed through multiple layers of hearsay resulted in the issuance of a search warrant unsupported by probable cause.
As Mathis concedes, hearsay evidence may form the basis for a probable cause determination.
See, e.g., Jones v. United States,
To bolster his argument, Mathis points to the Court’s discussion in Jones:
In testing the sufficiency of probable cause for an officer’s action even without a warrant, we have held that he may rely upon information received through an informant, rather than upon his direct observation, so long as the informant’s statement is reasonably corroborated by other matters within the officer’s knowledge.
Jones,
Next we consider the argument that because an unknown number of law enforcement agents were involved in transmitting the informant’s tips from the witnesses to Walden, the magistrate judge had no basis for determining the reliability (or in one instance, the identity
1
) of these links in the hearsay chain, and thus, no substantial basis upon which to conclude
*1205
the underlying tips were reliable. We restate that multiple layers of hearsay may form the basis of a finding of probable cause.
$149,442.43 in U.S. Currency,
Rugendorf v. United States,
Generally, we give considerable deference to a magistrate’s determination of probable cause; a reviewing court’s only duty is “to ensure that the magistrate had a substantial basis for concluding that probable cause existed.”
Gates,
In reviewing the denial of Mathis’s motion to suppress, we uphold a district court’s findings of fact unless they are clearly erroneous.
United States v. Danhauer,
The second cooperating witness (CW # 2) informed an FBI special agent that he or she had known Mathis for over two years and had seen Mathis sell methamphetamine at least twenty-five times between approximately February 1999 and August 2000. During the same period, CW #2 purportedly witnessed Mathis trade drugs for stereos and other items and overheard a conversation where Mathis claimed he routinely cooked methamphetamine at his residence. CW # 2 further asserted that he or she observed a dark colored, 1968 Chevrolet truck and a white truck with red paint dots on it at Mathis’s home and that a network of video cameras and police scanners were operating whenever CW # 2 was present at the residence.
Professing to have known Mathis for over three years, the third cooperating witness (CW # 3) stated that he or she had personally observed Mathis sell methamphetamine over fifty times, including a sale in January 2001. CW # 3’s observations of the quantity of methamphetamine Mathis generally sold in a transaction, Mathis’s willingness to accept goods in exchange for methamphetamine, his use of a network of video cameras and police scanners, his admission that methamphetamine was cooked at the residence, and that a white truck with red painted dots was present at the residence, all corroborate CW #2’s observations. In addition, Investigator Walden drove by Mathis’s residence in March of 2001 and observed a 1968 pickup fitting CW # 2 and CW # 3’s description. Lastly, cooperating witness # 4 (CW # 4), in late January 2001, informed the FBI of his personal knowledge that Mathis had distributed and continued to distribute significant quantities of methamphetamine, and that he or she had obtained methamphetamine from Mathis on a few occasions.
In summary, the district court found that the affidavit contained reliable information provided to law enforcement by the confidential informants; that each cooperating witness’ basis of knowledge had been stated, i.e., each personally knew Mathis and his residence; that the information provided by the informants was internally corroborated in several respects; and that Walden had extensive law enforcement experience, including training in investigations of illegal narcotics. On these grounds, the court determined that sufficient facts were available to establish a substantial basis to believe that evidence of a crime would be found at Mathis’s residence. Our review of the affidavit and the record does not persuade us that these findings of fact were erroneous. Furthermore, we conclude that given all the circumstances set forth in the affidavit, the magistrate had a substantial basis upon which to conclude that there was a fair probability that contraband or evidence of illegal activity would be present at Mathis’s residence at the time the search warrant was issued. We therefore conclude that the magistrate’s reliance on hearsay information as a basis for probable cause to support the first search warrant was not in error.
B
As for Mathis’s argument that the evidence in the affidavit was stale, we have previously held that “[p]robable cause to
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search cannot be based on stale information that no longer suggests that the items sought will be found in the place to be searched.”
Snow,
Mathis’s argument fails .on several grounds. First, we reject Mathis’s claim that the information provided by CW # 2 and CW # 3 are contradictory, simply because the last date on which each witness claims to have seen Mathis’s illegal activities differs. Mathis has offered no evidence beyond theorizing that CW # 2 and CW # 3 might have been in a relationship and therefore might have been at the residence at the same time that the dates should match.
Second, Mathis ignores our case law, which has firmly established that “whether information is too stale to establish probable cause depends on the nature of the criminal activity, the length of the activity, and the nature of the property to be seized.”
Snow,
We reject also Mathis’s contention that the information relied upon by the magistrate was unsubstantiated and therefore unreliable. Walden himself verified that a few days before the search warrant was executed, a particular truck, believed to be stolen and described by CW # 2 and CW # 3, was still present at Mathis’s residence; as a result, at least part of CW # 2 and CW # 3’s information was confirmed immediately prior to the warrant’s execution. For the foregoing reasons, it is quite clear to us that the information contained in the affidavit was not impermissibly stale or unreliable such as would preclude establishment of probable cause.
In sum, we affirm the district court’s determination that the first warrant issued was supported by probable cause; it is therefore unnecessary to address the district court’s alternative analysis concerning the
Leon
good faith exception for warrants issued without probable cause.
United States v. Leon,
*1208 II
The second general allegation of error is that the district court erred in denying Mathis’s motion to compel disclosure of the identities of CW # 2 and CW # 3. In addition to the appeal of the district court’s denial, Mathis has filed a petition with this court asking to supplement the record on appeal to include a transcript of the in camera hearing conducted by the district court, at which the identities of CW #2 and CW #3 were disclosed. We review the district court’s exclusion of evidence for an abuse of discretion.
United States v. Davis,
Underlying Mathis’s request for disclosure is his contradiction theory; specifically, the information from CW # 2 and CW # 3 is strikingly similar in all aspects except for the last date on which they reportedly observed Mathis’s drug activities. Given that the witnesses’ observations parallel in all other respects, Mathis argues, it stands to reason that they were present in the Mathis residence at the same time and might even be husband and wife. He concludes that because these witnesses were likely present in his residence at the same time, their information should match in all respects, including the dates each witness observed his illegal undertakings. Mathis tells us that the alleged contradiction between CW #2 and CW # 3 is critically important because the information provided by these two witnesses was integral to the magistrate judge’s determination that probable cause existed. Because he claims the relationship between the two cooperating witnesses is crucial to his contradiction theory, Mathis asserts it is essential to his defense that the identities of these two cooperating witnesses be revealed.
However, the district court considered these arguments at an in camera hearing and determined that the revelation of the informant’s identities was not relevant to Mathis’s defense. Additionally, the court found that Mathis had provided no evidence that CW #2 and CW #3 were at his residence at the same time. Regarding Mathis’s hypothesis that CW #2 and CW # 3 may have been husband and wife and therefore should have identical observations, the court correctly observed, “[e]ven a husband and wife are not always at the same location at the same time. Simply because [CW # 2 and CW # 3’s] observations are not identical does not mean they are incorrect or inconsistent.” United States v. Mathis, CR-02-00044, at 13, Aug. 2, 2002. We agree.
Mathis has marshaled the mere speculation that if CW # 2 and CW # 3 were in a relationship, any inconsistencies in their observations of Mathis’s illegal activities renders their accounts contradictory and unreliable. Such speculation is insufficient to warrant the disclosure of the identities of confidential informants. We conclude that the district court did not abuse its discretion in denying Mathis’s motion to compel disclosure of the identities of CW # 2 and CW # 3. Further, we deny Mathis’s motion to supplement the record on *1209 appeal with the transcript of the district court’s in camera hearing.
III
AFFIRMED.
Notes
. In the affidavit, Walden does name the law enforcement agents from whom he received CW # 1-3's information; nonetheless, in the case of CW # 4, the affidavit does not provide the identity of or information regarding the reliability of the law enforcement agent(s) who furnished Walden with CW # 4’s story.
