Collateral Estoppel Law and Legal Definition

Collateral estoppel is the legal doctrine that holds that the determination of the facts litigated between the parties to a proceeding are binding and conclusive on those parties in any future litigation. It is also referred to as "issue preclusion". The constitutional ban on double jeopardy includes the right to plead collateral estoppel.

Under collateral estoppel, once a court has decided an issue of fact or law necessary to its judgment, that decision may preclude relitigation of the issue in a suit on a different cause of action involving a party to the first case. The collateral estoppel bar is inapplicable when the claimant did not have a 'full and fair opportunity to litigate' the issue decided by the other court. Thus, a claimant can file a federal suit to challenge the adequacy of state procedures. Ordinarily, collateral estoppel is an affirmative defense that must be raised by the party seeking to use it, or else it is waived.

Non-mutual, defensive use of collateral estoppel occurs when a defendant seeks to prevent a plaintiff from relitigating an issue the plaintiff has previously litigated unsuccessfully in another action against a different party. Non-mutual, offensive collateral estoppel occurs when a plaintiff seeks to foreclose a defendant from relitigating an issue that the defendant has previously litigated unsuccessfully in another action against a different party. The U.S. Supreme Court has cautioned that non-mutual, offensive collateral estoppel should not be applied where: (1) a plaintiff in the second action could have easily joined in the earlier suit; or (2) where the application of offensive estoppel would be unfair to a defendant. Application of these doctrines varies by jurisdiction, so local laws should be consulted.

"Collateral estoppel applies '[when] an issue of fact or law is actually litigated and determined by a valid and final judgment . . . . A judgment is not conclusive in a subsequent action as to issues which might have been but were not litigated and determined in the prior action.'" Green v. Dupuis, 2005 U.S. Dist. LEXIS 26320 ( E.D. Mich. Oct. 24, 2005)