“[W]here an issue raised as to the existence of the act or fact denounced has been tried in a criminal proceeding, instituted by the United States, and a judgment of acquittal has been rendered in favor of a particular person, that judgment is conclusive in favor of such person, on the subsequent trial of a suit in rem by the United States, where, as against him, the existence of the same act or fact is the matter in issue, as a cause for the forfeiture of the property prosecuted in such suit in rem. It is urged as a reason for not allowing such effect to the judgment, that the acquittal in the criminal case may have taken place because of the rule requiring guilt to be proved beyond a reasonable doubt, and that, on the same evidence, on the question of preponderance of proof, there might be a verdict for the United States, in the suit in rem. Nevertheless, the fact or act has been put in issue and determined against the United States; and all that is imposed by the statute, as a consequence of guilt, is a punishment therefor. There could be no new trial of the criminal prosecution after the acquittal in it; and a subsequent trial of the civil suit amounts to substantially the same thing, with a difference only in the consequences following a judgment adverse to the claimant.” Id., at 443.
Although the language quoted above incorporates notions of both collateral estoppel and double jeopardy, the Coffey Court did not identify the precise legal foundation for the rule of preclusion it announced. Perhaps for this reason, later decisions of this Court have reflected uncertainty as to the exact scope of the Coffey holding.
In Helvering v. Mitchell, 303 U. S. 391 (1938), the Court considered the preclusive effect of a prior criminal acquittal on a subsequent action for a monetary penalty. The defendant taxpayer in Mitchell was acquitted of charges that he willfully attempted to evade and defeat the income tax by