Franks v. Delaware: Challenging False Warrant Statements

Franks v. Delaware, 438 U.S. 154 (1978)

Supreme Court of the United States · Fourth Amendment / warrant affidavits

The hearing threshold

A defendant must make a substantial preliminary showing that the affiant knowingly, intentionally, or recklessly included a false statement in a warrant affidavit, and that the statement was necessary to probable cause. The challenge requires supporting evidence, not merely a disagreement with the affidavit. Negligence or innocent mistake is insufficient.

What happens at the hearing

If intentional or reckless falsity is established by a preponderance of the evidence, and the affidavit without the false material does not establish probable cause, the warrant must be voided and the resulting evidence excluded.

Research checklist

Identify the exact statement, evidence contradicting it, evidence of the affiant’s state of mind, and the remaining probable-cause facts. Claims involving omitted facts require jurisdiction-specific research into later decisions; Franks does not automatically invalidate every incomplete affidavit.

Read the opinion

https://www.law.cornell.edu/supremecourt/text/438/154

Educational information, not legal advice. Discuss the record, local rules, and deadlines with qualified counsel.