A Franks hearing is not a constitutional requirement in and of itself, but it is a constitutional remedy.
This means that while the Constitution doesn't say "a defendant must have a Franks hearing," the hearing itself is a procedure designed to protect a defendant's Fourth Amendment rights.
The Fourth Amendment protects people from unreasonable searches and seizures by requiring that warrants be supported by probable cause and a sworn affidavit. If a police officer knowingly or recklessly lies or omits critical information in that affidavit, they are violating the spirit and intent of the Fourth Amendment.
The Franks hearing is the court-created mechanism for a defendant to challenge that alleged misconduct. If the defendant can prove the officer acted improperly, the warrant is invalidated, and any evidence seized is suppressed. Without this remedy, the Fourth Amendment's warrant requirement would be meaningless because officers could simply lie in affidavits without consequence.
This means that while the Constitution doesn't say "a defendant must have a Franks hearing," the hearing itself is a procedure designed to protect a defendant's Fourth Amendment rights.
The Fourth Amendment protects people from unreasonable searches and seizures by requiring that warrants be supported by probable cause and a sworn affidavit. If a police officer knowingly or recklessly lies or omits critical information in that affidavit, they are violating the spirit and intent of the Fourth Amendment.
The Franks hearing is the court-created mechanism for a defendant to challenge that alleged misconduct. If the defendant can prove the officer acted improperly, the warrant is invalidated, and any evidence seized is suppressed. Without this remedy, the Fourth Amendment's warrant requirement would be meaningless because officers could simply lie in affidavits without consequence.