SC20187 - State v. Smith (Felony Murder and Manslaughter; Motion to correct illegal sentence; Whether rule established in State v. Polanco requiring vacatur as remedy for cumulative convictions in violation of double jeopardy protections applies retroactively."The dispositive issue in this appeal is whether the trial court had subject matter jurisdiction to entertain a motion to correct an illegal sentence when the defendant, Jeffrey Smith, claimed that the sentencing court improperly failed to follow State v. Polanco, 308 Conn. 242, 255, 61 A.3d 1084 (2013), in which this court exercised its supervisory power to hold that the proper remedy for cumulative convictions that violate the double jeopardy clause is to vacate one of the convictions. In 2005, the defendant was convicted, after a jury trial, of felony murder and manslaughter in the first degree, among other crimes. The trial court, Schimelman, J., merged the conviction for manslaughter with the felony murder conviction and sentenced the defendant to sixty years in prison on the felony murder charge. In 2015, the defendant filed a motion to correct an illegal sentence in which he contended that the sentence was illegal under the Polanco supervisory rule because the court merged the convictions instead of vacating the conviction on the manslaughter charge. The trial court, Strackbein, J., concluded that, because Polanco was decided pursuant to this court's supervisory authority, it did not apply retroactively. Accordingly, the trial court denied the defendant's motion. The defendant appealed, and the Appellate Court affirmed the judgment of the trial court. See State v. Smith, 180 Conn. App. 371, 384, 184 A.3d 831 (2018). We then granted the defendant's petition for certification to appeal to this court, limited to the following issue: "Does this court's holding in State v. Polanco, [supra, 255], readopting vacatur as a remedy for a cumulative conviction that violates double jeopardy protections, apply retroactively?" State v. Smith, 330 Conn. 908, 193 A.3d 559 (2018). In its brief to this court, the state claims for the first time that the trial court lacked subject matter jurisdiction to entertain the defendant's motion to correct an illegal sentence because the motion sought only to modify the defendant's conviction, not his sentence. We agree with the state's jurisdictional claim, and, accordingly, we conclude that the form of the Appellate Court's judgment affirming the judgment of the trial court was improper. We reverse the judgment of the Appellate Court and remand the case to that court with direction to remand the case to the trial court with direction to dismiss the defendant's motion to correct an illegal sentence.")