The question of the competence of a witness is fundamental to his or her testimony. If the witness is deemed to be an incompetent witness, then his or her testimony will be excluded from the trial process thereby omitting his or her voice from criminal proceedings.  In Ireland, there is no explicit legislative test for competence nor is it linked specifically to age or disability. The test derives from s. 27 Criminal Evidence Act 1992 and the case of  O’Sullivan v Hamill [1998] 2 IR 9.

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27(1) Criminal Evidence Act 1992 provides that evidence of children under 14 and persons with an intellectual disability will be admitted otherwise ‘on oath or affirmation if the court is satisfied that he is capable of giving an intelligible account of events which are relevant to those proceedings.’  It is therefore the ability to give an intelligible account of events which are relevant to the proceedings, which has emerged as the competency test in this jurisdiction.

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s.28 Criminal Evidence Act 1992 made corroboration of child witnesses and witnesses with an intellectual disability discretionary and also allowed a child or witness with an intellectual disability to corroborate the testimony of another child. 

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