Does a jury have a duty to ascertain that a guilty plea is voluntary before accepting the plea?

Generally, a trial court has a duty to ascertain that a guilty plea is voluntary before accepting the plea. Boyken v. Alabama, 89 S.Ct. 1709, 1711 (1969). Because the guilty plea constitutes a waiver of several constitutional rights (e.g. privilege against self incrimination; right to trial by jury; right to confront one's accusers), the inquiry into voluntariness is constitutionally mandated. Id. at 1712.