United States v. Miller
The foundational third-party-doctrine decision holding that a bank customer had no Fourth Amendment expectation of privacy in business records maintained by banks.
Executive Summary
Miller remains important whenever investigators seek records held by financial institutions or other service providers. But it is a starting point, not a universal answer for modern digital data.
Federal agents obtained a suspect’s bank records through subpoenas that did not satisfy the governing statute. The Supreme Court held that the Fourth Amendment was not implicated because the records were the banks’ business documents and contained information the customer had voluntarily conveyed to the banks. Miller became a foundation of the third-party doctrine, although later digital-era decisions—especially Carpenter v. United States—refused to extend that reasoning mechanically to deeply revealing, comprehensive data.
Facts
Mitch Miller was investigated for operating an unregistered distillery and related tax offenses. Treasury agents obtained copies of checks, deposit slips, financial statements, and monthly bank records from two banks.
The government used subpoenas directed to the banks. The court of appeals concluded that the subpoenas were defective under federal law and suppressed the records.
The Supreme Court addressed whether Miller could invoke the Fourth Amendment to challenge government acquisition of records maintained by the banks.
Procedural History
Miller was convicted in federal court. The Fifth Circuit reversed after finding the subpoenas defective. The Supreme Court reversed the court of appeals, concluding that Miller had no Fourth Amendment interest in the bank records.
Constitutional Question
Does a bank customer have a Fourth Amendment expectation of privacy in financial records maintained by banks when the records contain information voluntarily conveyed to those institutions?
Holding
No. The records were business documents of the banks, not Miller’s private papers, and the information had been conveyed to the banks in the ordinary course of business. Miller therefore could not suppress them under the Fourth Amendment.
Court’s Reasoning
The Court distinguished the contents of private communications from information exposed to a business. Checks and deposit slips were commercial instruments used in transactions, and the banks kept their own records of those transactions.
A person who reveals information to a third party assumes the risk that the recipient may convey it to the government. That principle echoed United States v. White and later supported Smith v. Maryland.
The Court’s holding addressed the Fourth Amendment. Statutes may impose procedures and privacy protections beyond the constitutional minimum.
What the Decision Does Not Hold
- Carpenter declined to extend the doctrine categorically to historical cell-site location information, emphasizing its depth, reach, and involuntary character.
- The decision does not eliminate statutory requirements governing bank records, financial privacy, subpoenas, warrants, notice, or nondisclosure.
- A customer may still raise challenges based on scope, relevance, privilege, state constitutional law, or statutes even when the federal Fourth Amendment does not control.
Agency Guidance
Agency policy and training should translate the decision into specific, reviewable procedures:
Primary Sources and Further Reading
Educational information only; not legal advice. Agencies should confirm current federal, state, and local authority before relying on this material.