When an accused person, particularly an unrepresented youth, discloses a defence during plea proceedings, the trial court must stop the proceedings and refer the matter to trial for evidence to be called; it is impermissible to proceed to conviction on a guilty plea in the face of a defence. A trial court has a positive duty to ensure that charges match the facts disclosed, particularly for unrepresented accused persons, and must examine the essential elements of the offence charged against the explanation given. Section 66 of the Criminal Law Code (aggravated indecent assault) requires absence of consent as a key element; where consent is present, the charge cannot be sustained. For sexual conduct with young persons aged 12-14, s64 exempts charges of rape or aggravated indecent assault where there is evidence that the young person was capable of giving consent and gave consent. The proper charge for consensual sexual conduct with children aged 12-18 is under s70 of the Criminal Law Code (as amended), where consent is no defence. Procedural irregularities that go to the root of the case vitiate the entire proceedings and render the conviction unsafe.