## Facts

- Los Angeles police suspected Max Janis of illegal bookmaking and obtained a state search warrant for bookmaking materials based on an officer’s affidavit.
- Police executed the warrant and seized $4,940 in cash and wagering records.
- The officer informed the Internal Revenue Service (IRS) of the arrest and provided the seized records.
- Using those records, the IRS estimated Janis’s federal wagering excise tax liability under I.R.C. § 4401 by extrapolating from a five-day sample to a 77-day period, assessed tax, and levied on the $4,940 as partial payment.
- In the ensuing state criminal case, a California court found the warrant affidavit defective, quashed the warrant, and ordered the seized items returned except for the $4,940.
- Janis filed an administrative refund claim and then brought a federal civil refund action challenging the assessment as based on evidence obtained in violation of the Fourth Amendment.

## Issues

1. Whether the exclusionary rule bars the United States from using, in a federal civil tax proceeding, evidence unconstitutionally seized by state law enforcement officers.
2. Whether extending the exclusionary rule to this intersovereign civil context would yield sufficient deterrence to justify the costs of excluding probative evidence.

## Decision

- The Supreme Court reversed the Ninth Circuit in a 5–3 decision.
- The Court held that the exclusionary rule should not be extended to prohibit federal civil tax use of evidence unlawfully seized by state officers.
- The Court concluded that any added deterrence from excluding the evidence in a federal civil proceeding was too small to justify the resulting costs to tax enforcement and truth-finding.

## Legal Principles

- The exclusionary rule is a judicially created remedial doctrine principally aimed at deterring future unlawful police conduct, not an automatic constitutional requirement applicable in every proceeding.
- Whether to apply the exclusionary rule in a new setting turns on a cost–benefit analysis: the expected deterrence must outweigh the societal costs of exclusion.
- In an intersovereign setting—state officers’ unconstitutional seizure followed by federal civil use—incremental deterrence is limited because state officers are already deterred by suppression in criminal cases and are unlikely to be influenced by consequences in federal civil tax litigation.
- Absent sufficient marginal deterrence, the federal government may use relevant evidence in a civil tax proceeding even if state officers obtained it through an unconstitutional search.

## Conclusion

The Court declined to extend the exclusionary rule to bar the federal government from using evidence unlawfully seized by state officers in a federal civil tax case, reasoning that the slight additional deterrent effect did not justify the substantial costs of excluding reliable evidence in civil tax administration.


United States v. Janis, 428 U.S. 433 (1976)