Martinez appeals to this Court. He contends that this Court has jurisdiction to consider his appeal pursuant to Code § 8.01-670(A)(3). This Court granted the appeal by order dated June 4, 2018 and directed the parties to address the issue of this Court's jurisdiction to consider the appeal.
"Subject matter jurisdiction is the authority granted through constitution or statute to adjudicate a class of cases or controversies." Gray v. Binder , 294 Va. 268, 275, 805 S.E.2d 768 (2017) (citation and internal quotation marks omitted). "A challenge to subject matter jurisdiction presents a question of law that we review de novo." Id.
Undisputedly, this Court has jurisdiction over an appeal from "a final judgment in [a] civil case." Code § 8.01-670(A)(3). However, equally undisputedly, in a criminal case, with the exception of cases in which the death penalty has been imposed, an appeal lies first with the Court of Appeals. Code §§ 17.1-406(A)(i) and 19.2-317(A). Thus, we must determine whether this appeal is from a purported judgment in a civil case or a criminal case.
"[I]t is the nature of the method employed to seek relief from a criminal conviction and the circumstances under which the method is employed that determine whether an appeal is civil or criminal in nature." Commonwealth v. Southerly , 262 Va. 294, 299, 551 S.E.2d 650 (2001). When a criminal defendant submits "an appeal from the conviction itself or from action on motions filed and disposed of while the trial court retains jurisdiction over the case, the appeal is criminal in nature." Id.
*531The determination of one's competency to stand trial occurs while the circuit court retains jurisdiction over the criminal prosecution. Trial competency determinations are necessary because "the Due Process Clause of the Fourteenth Amendment prohibits the criminal prosecution of a defendant who is not competent to stand trial." Dang v. Commonwealth , 287 Va. 132, 144, 752 S.E.2d 885 (2014) (emphasis added) (citation and internal quotation marks omitted). A finding of incompetency to stand trial requires "suspension of the criminal trial until such time, if any, that the defendant regains the capacity to participate in his defense and understand the proceedings against him." Medina v. California , 505 U.S. 437, 448, 112 S.Ct. 2572, 120 L.Ed.2d 353 (1992) (emphases added).
Additionally, as provided in Code §§ 19.2-169.1 through -169.3, a trial competency determination is initiated by criminal charges, occurs after an attorney is appointed, suspends the criminal prosecution, permits the dismissal of certain charges, and asks whether the defendant "lacks substantial capacity to understand the [criminal ] proceedings against him or to assist his attorney in his own defense" of criminal charges. Code § 19.2-169.1(A) (emphasis added); see Beck v. Angelone , 261 F.3d 377, 388 (4th Cir. 2001) (recognizing that neither mental illness, low intelligence, mental deficiency, irrational behavior, volatile behavior, nor the need for anti-psychotic medication can establish incompetency to stand trial). Accordingly, we conclude that the determination of one's competency to stand trial is "part of [a] purely criminal process," and the appeal from such determination is criminal in nature. Therefore, this Court does not have jurisdiction to consider the appeal in this case.
Further, there is a question of whether a final order was entered in the circuit court. Under Code § 8.01-677.1, this Court may transfer an appeal to the Court of Appeals that was filed in this Court, if the Court of Appeals has "appropriate jurisdiction for further proceedings in accordance with [its] rules." (Emphasis added.) The Court of Appeals' jurisdiction is limited, in pertinent part, to the appeal of "any final conviction in a circuit court of a traffic infraction or a crime." Code § 17.1-406(A)(i) (emphasis added); see also West v. Commonwealth , 249 Va. 241, 243, 455 S.E.2d 1 (1995) ("[C]riminal appeals lie only to final judgments."). There has not been a final conviction entered in this case. Because there has been no final conviction, we decline to transfer the case to the Court of Appeals and will dismiss the appeal.
Accordingly, for the above reasons, we dismiss the appeal, without prejudice, and remand this case to the circuit court for further proceedings.
This order shall be published in the Virginia Reports and certified to the Circuit Court of the City of Williamsburg and James City County.