SC20727 - Tatum v. Commissioner of Correction ("'[M]istaken eyewitness identification testimony is by far the leading cause of wrongful convictions.' State v. Guilbert, 306 Conn. 218, 249–50, 49 A.3d 705 (2012). Recognizing the developments in the cognitive science of eyewitness identification, this court has recently established new rules for cases in which eyewitness identification evidence is proffered. Specifically, in Guilbert, we determined that "expert testimony on eyewitness identification is admissible upon a determination by the trial court that the expert is qualified and the proffered testimony is relevant and will aid the jury." Id., 226. In doing so, we overruled earlier decisions from this court, which held that the factors affecting eyewitness identification were within the knowledge of an average juror. See id., 226, 229, 251–53. We reasoned that our prior case law was "out of step with the widespread judicial recognition that eyewitness identifications are potentially unreliable in a variety of ways unknown to the average juror. This [broad-based] judicial recognition tracks a near perfect scientific consensus. The extensive and comprehensive scientific research, as reflected in hundreds of peer reviewed studies and meta-analyses, convincingly demonstrates the fallibility of eyewitness identification testimony and pinpoints an array of variables that are most likely to lead to a mistaken identification." (Footnotes omitted.) Id., 234–36. We also noted that a trial court retains discretion to provide "focused and informative" jury instructions on the fallibility of eyewitness identification evidence. Id., 257–58. Four years later, in State v. Dickson, 322 Conn. 410, 141 A.3d 810 (2016), cert. denied, 582 U.S. 922, 137 S. Ct. 2263, 198 L. Ed. 2d 713 (2017), we further developed protections against inherently suggestive identifications. In doing so, we overruled this court's 1991 holding in this petitioner's direct appeal related to a first-time, in-court cross-racial eyewitness identification. See id., 434–36 (overruling in part State v. Tatum, 219 Conn. 721, 595 A.2d 322 (1991)). We concluded that "any [first-time] in-court identification by a witness who would have been unable to reliably identify the [petitioner] in a nonsuggestive out-of-court procedure constitutes a procedural due process violation." (Emphasis in original.) State v. Dickson, supra, 426 n.11. The sole issue in this certified appeal is whether the principles this court set forth in Guilbert and Dickson apply retroactively to the petitioner's case on collateral review. We conclude that the principles articulated in Dickson do. Accordingly, we reverse in part the judgment of the Appellate Court.")