Who may Testify as Witness: As per Lawkidunya and according to Section 3 of QSO Qanoon-e-Shahadat & Section 118 of the Evidence Act, all persons shall be competent to testify unless the Court considers that they are prevented from understanding the questions put to them, or from giving rational answers to those questions, by tender years, extreme old age, disease, whether of body or mind or any other cause of the same kind:
Provided that a person shall not be competent to testify if he has been convicted by a Court for perjury or giving false evidence:
Provided further that the provisions of the first proviso shall not apply to a person about whom the Court is satisfied that he has repented thereafter and mended his ways:
Provided further that the Court shall determine the competence of a witness in accordance with the qualifications prescribed by the injunctions of Islam as laid down in the Holy Quran and Sunnah for a witness, and. where such witness is not forthcoming the Court may take the evidence of a witness who may be available.
Explanation: A lunatic is not incompetent to testify unless he is prevented by his lunacy from understanding the questions put to him and giving rational answers to them.
Who may Witness in Law
A witness is a person who deposes some relevant fact in an issue or testifies in order to prove or disprove any matter in question. It is worth noting here that, the competency to testify as a witness is a condition precedent to administer witness on oath, and is a distinct matter from the credibility of the witness.