Chiaverini v. City of Napoleon

In Chiaverini v. City of Napoleon, the U.S. Supreme Court addressed whether a malicious prosecution claim under the Fourth Amendment requires a plaintiff to show that the entire criminal proceeding was unsupported by probable cause, or if it's sufficient to show a single baseless charge within a multi-charge case. Jascha Chiaverini was charged with multiple offenses after a disputed transaction involving a ring. He alleged some charges lacked probable cause and were brought maliciously. The Sixth Circuit ruled against him, requiring the entire proceeding to lack probable cause. The Supreme Court, however, ruled in favor of Chiaverini, holding that a Fourth Amendment malicious prosecution claim can be established by proving that a single charge within a criminal proceeding lacked probable cause, even if other charges were valid.

The Supreme Court ruled unanimously that a malicious prosecution claim under the Fourth Amendment can be based on an individual baseless charge, even if other charges in the same proceeding were supported by probable cause.

The central dispute was whether a Fourth Amendment malicious prosecution claim requires demonstrating a lack of probable cause for the criminal proceeding as a whole, or merely for one individual charge within that proceeding.

This decision provides greater protection for individuals against groundless charges by allowing them to challenge specific charges rather than an entire prosecution. It clarifies the scope of Fourth Amendment claims and may lead to more careful charging decisions by prosecutors to avoid including unsupported charges.