Non-mutual collateral estoppel is the exercise of collateral estoppel by a person who was not a party to the prior litigation. That person might be a defendant (asserting it defensively, thus “defensive non-mutual collateral estoppel”), or a plaintiff (asserting it offensively, thus “offensive non-mutual collateral estoppel”). Non-mutual collateral estoppel (or “NMCE”) is the modern trend but is still not permitted in some jurisdictions. However, even where permitted, NMCE cannot be used against a party unless that party (or their privy) had their day in court on that issue in the prior litigation. Due process prohibits the exercise of collateral estoppel against a person who was not a party or a privy to the prior litigation because they never had a prior opportunity to be heard on the issue. See Parklane, n. 7.
Thus, NMCE is prohibited in the scenarios in the bottom row, where the person against whom NMCE is being asserted (or their privy) did not litigate in suit 1. But where a party (or privy) did litigate in suit 1 (the row above the bottom row), NMCE might be ok. Even then, however, a court must still determine whether that party had a “full and fair opportunity to litigate.” Parklane. The Parklane court lists a number of considerations in determining when NMCE is appropriate. See Parklane.
|Defensive NMCE||Offensive NMCE|
|NMCE MIGHT BE OK. Court may be able to permit NMCE b/c asserted against party who lost on issue in prior litigation. See Blonder-Tongue and Parklane.||A. Same P, different Ds
Like Blonder-Tongue. P litigated & lost issue in suit 1. Court might be able to permit.
|B. Same D, different Ps
Like Parklane. D litigated and lost issue in suit 1. Court might be able to permit.
|NMCE PROHIBITED. Cannot assert NMCE against party who did not participate (themselves or their privy) in the prior litigation. See Parklane FN.7.||C. Same D, different Ps
Not possible b/c P2 didn’t litigate issue in suit 1, can’t be estopped (unless in privy with P1).
|D. Same P, different Ds
Not possible b/c D2 didn’t litigate issue in suit 1, can’t be estopped (unless in privy with D1).
Updated Apr. 16, 2015