Collateral Estoppel - Requirements

Issues or findings of fact, not conclusions of law, are subject to collateral estoppel only in certain cases. The issue against which collateral estoppel is claimed must be identical to an issue already litigated in the earlier case and must have been fully litigated at that time. In addition, the court must have actually decided the issue. The decision on the issue must have been integral in the outcome of the original lawsuit. This last requirement assures the issue was vigorously litigated so that it is fair to prevent its relitigation in a second action because there is little likeli-hood that the results will be different the second time.

If an action has been settled by the agreement of the parties, most jurisdictions will not apply collateral estoppel, since the issues have not been fairly and fully litigated.