Collateral Estoppel

Collateral estoppel applies to prevent a person in a civil case from re-litigating an issue.  Once a court has decided an issue of fact or law necessary to its judgment, that decision will preclude re-litagation of that issue in a suit on a different cause of action involving a party to the first case.  A topic within this area that has been showing up in practice questions is that of mutuality.

Traditionally, collateral estoppel only applied where the party seeking to employ collateral estoppel and the party against whom collateral estoppel was being employed were both parties to the previous lawsuit.  If this were true it was said that there was mutuality among the parties.  This requirement has been abandoned by most courts in most circumstances.  For purposes of the MBE, you should understand 4 ways in which collateral estoppel may be used:

Defensive mutual collateral estoppel:  This is when collateral estoppel is used by the defendant from the first suit against the plaintiff from the first suit regarding issues that were previously litigated against the defendant in the first suit.

Defensive non-mutual collateral estoppel:  This is when collateral estoppel is used by a new defendant in a later suit regarding issues that were previously litigated against the plaintiff by a former defendant in a previous suit.

Offensive mutual collateral estoppel:  This is when collateral estoppel is used in a later suit by the plaintiff from the first suit against the defendant from the first suit regarding issues that had already been litigated in that first suit.

Offensive non-mutual collateral estoppel:  This is when collateral estoppel is used by a new plaintiff in a later suit against the defendant from a previous suit regarding issues that were previously litigated against that defendant in the previous suit.