The Court of Appeals found that the trial court erred in admitting testimony of the state’s fingerprint examiner where the expert failed to show he applied reliably applied the relevant methods and principles to the case, in violation of N.C. Evid. Rule 702(a)(3). Because the defendant failed to object at trial, the issue was reviewed for plain error only. The defendant could not show prejudice, so the court found no plain error and the conviction was affirmed. The testimony in Koiyan was similar to that of the fingerprint analyst in State v. McPhaul, 256 N.C. App. 303 (2017).