The Exclusionary Rule

One of the important issues that arise in a criminal prosecution where a search was conducted and incriminating evidence discovered is a motion to exclude the evidence. The bases for this motion is that the evidence is the product of an illegal search. An illegal search is conducted by the police when it violates the 4th amendment to the United States Constitution. The 4th amendment includes a provision prohibiting government intrusions by unreasonable searches and seizures and provides that the people should “be secure in their persons, houses, papers and effects, against unreasonable searches and seizures.”

The remedy in a criminal proceedings for a violation is the exclusion of evidence discovered and is called the Exclusionary Rule. When a court applies the rule the evidence seized in violation of the 4th amendment is barred from being used and often this will cause a dismissal of the charges.

The primary purpose of the exclusionary rule “is to deter future unlawful police conduct and thereby effectuate the guarantee of the Fourth Amendment against unreasonable searches and seizures.”[i] Without the rule police could violated the Constitution with no practical recourse by those whose 4th amendment rights have been violated.

The evidence which may be excluded can be direct or indirect recovered during a search, including physical objects, papers, and verbal statements.

There are two principle areas where illegal searches can be challenged. The first is when the search was conducted with a search warrant and the second is where the search was done without one under an exception to the search warrant requirement. While the standard for judging the legality of the search is the same the rules and the circumstances for challenging the justification of the search may differ.

Search Warrant

All searches with several notable exceptions must be made with the support of a valid search warrant. A search warrant is simply an order in writing, signed by a magistrate [Judge, Court Commissioner], usually directed to a peace officer, commanding him or her to search a location for property or other things and when discovered to bring them to the magistrate. As a practical matter the items discovered are returned to the magistrate in a list of recovered property rather than the actual discovered items

Good Faith Exception.

The good faith exception is a defense raised by the prosecution to overcome a defective search warrant. This defense applies where the defect was not caused by the police requesting the warrant and they were not aware that the warrant was not valid.[ii] In theory since there was a review by a magistrate before it was signed the need to deter police misconduct is relieved and the justification to apply the exclusionary rule is unnecessary.

The prosecution must show where there is an invalid warrant that the exception applies and that the police acted in, “good faith” reliance on the validity of the warrant unaware of the defect.[iii]


[i] United States v. Calandra (1974) 414 U.S. 338, 94 S.Ct. 613, 619, 626, 38 L.Ed.2d 561, 571, 579.

[ii] United States v. Leon (1984) 468 U.S. 897, 104 S.Ct. 3405, 82 L.Ed.2d 677

[iii] People v. Camarella (1991) 54 C.3d 592, 596, 286 C.R. 780, 818 P.2d 63; People v. Willis, supra, 28 C.4th 33