480 U.S. 340 (1987)
Illinois v. Krull is a pivotal case in the landscape of Fourth Amendment jurisprudence, as it clarifies the application of the exclusionary rule when it comes to evidence obtained under a statute subsequently ruled unconstitutional.
Can evidence obtained by law enforcement officers acting in reliance on a statute, later deemed unconstitutional, be admitted under the Fourth Amendment's exclusionary rule?
Evidence obtained in good faith reliance on a statute later held to be unconstitutional is admissible, according to the 'good faith' exception to the exclusionary rule.
The Supreme Court held that the good faith exception to the exclusionary rule applies when police act in objectively reasonable reliance on the legality of a statute that is later declared unconstitutional.
Illinois v. Krull is significant for establishing that the exclusionary rule does not automatically apply to evidence gathered under a statute later invalidated for being unconstitutional. The case expands the good faith exception, further defining the limits of police accountability for malfunction in legislation rather than misuse of judicial power or judgment. For law students, this case provides insight into how the judiciary interprets constitutional protections in the context of evolving societal and legislative landscapes.