In Irizarry v. Office of General Counsel, 934 A.2d 143 (Pa. Cmwlth. 2007) the Court held that in Pennsylvania, collateral estoppel applies when: (1) an issue of law or fact decided in a prior action is identical to one presented in a later action; (2) the prior action resulted in a final judgment on the merits; (3) the party against whom collateral estoppel is asserted was a party to the prior action or is in privity with a party to the prior action; (4) the party against whom collateral estoppel is asserted had a full and fair opportunity to litigate the issue in the prior action. Irizarry v. Office of General Counsel, 934 A.2d 143 (Pa. Cmwlth. 2007).