Using Suppression Hearing Testimony to Prove Good Faith Under United States V. Leon

96 Pages Posted: 26 Mar 2006

See all articles by John E. Taylor

John E. Taylor

West Virginia University College of Law


Imagine a narcotics prosecution based largely on evidence obtained under the authority of a search warrant. At the suppression hearing, the defendant argues that the warrant is invalid under Illinois v. Gates because the affidavit supporting the warrant application failed to provide the magistrate with even a "substantial basis for concluding that probable cause existed." The defendant further argues that the fruits of the search must be suppressed despite the United States v. Leon good faith exception because the affidavit was "so lacking in indicia of probable cause as to render official belief in its existence entirely unreasonable." When the trial court seems inclined to accept these arguments, the prosecution offers to introduce testimony from the affiant officer about information supporting probable cause that she knew at the time of the warrant application but neglected to present to the magistrate. It is clear that if this additional information had been included in the warrant application, the warrant would have been supported by probable cause. Does United States v. Leon allow the prosecution to use the affiant's suppression hearing testimony to cure the probable-cause deficiencies in the affidavit and establish the officer's good faith?

Most courts that have explicitly addressed this issue have adopted bright-line rules, holding either that information known to the officer but not communicated to the magistrate can always be used to establish good faith or that it never can. Although such categorical rules are simple and easy to apply, I argue that an intermediate approach is more faithful to Leon and to the policies that underlie the Fourth Amendment's warrant requirement. In my view, the propriety of using suppression hearing testimony to establish the officer's good faith ultimately depends on whether there can be such a thing as an "objectively reasonable mistake" in the warrant application process. Focusing on this question leads me to conclude that information known to the affiant officer but never presented to the magistrate can establish the officer's good faith only where the omission resulted from a reasonable mistake in preparing the warrant application and the officer's knowledge of the information at the time of the warrant application is proven by clear and convincing evidence.

Keywords: Leon, good faith exception, exclusionary rule

Suggested Citation

Taylor, John E., Using Suppression Hearing Testimony to Prove Good Faith Under United States V. Leon. Kansas Law Review, Vol. 54, pp. 155-250, 2005 . Available at SSRN:

John E. Taylor (Contact Author)

West Virginia University College of Law ( email )

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