SC19923 - Mendillo v. Tinley, Renehan & Dost, LLP ("In this appeal, we consider whether the Superior Court has subject matter jurisdiction over a declaratory judgment action brought as a collateral attack on a judgment of the Appellate Court concerning the plaintiff, George E. Mendillo. The plaintiff appeals from the judgment of the trial court dismissing his declaratory judgment action against the defendants, the law firm of Tinley, Renehan & Dost, LLP (law firm), and the Connecticut Appellate Court. On appeal, the plaintiff, who is an attorney, claims that the trial court improperly concluded that his challenge to the Appellate Court’s interpretation of rule 4.2 of the Rules of Professional Conduct in Sowell v. DiCara, 161 Conn. App. 102, 127 A.3d 356, cert. denied, 320 Conn. 909, 128 A.3d 953 (2015), was barred by the doctrine of sovereign immunity. We, however, do not reach the sovereign immunity issues raised by the plaintiff because we agree with the defendants’ alternative jurisdictional argument, and conclude that the plaintiff’s collateral attack on Sowell in this declaratory judgment action is nonjusticiable under Valvo v. Freedom of Information Commission, 294 Conn. 534, 985 A.2d 1052 (2010). Accordingly, we affirm the judgment of the trial court")