A Handbook for Public Prosecutors

23. Competency, Compellability and Privilege

Chapter 23 COMPETENCY, COMPELLABILITY AND PRIVILEGE As a large body of evidence which the prosecution adduces in courts of law consists of oral evidence, it is necessary for a public prosecutor to know which of those persons may be allowed to testify in court if they have some knowledge relevant to the case. There are some witnesses who can testify but are not compellable witnesses. Then there are witnesses who, though competent to testify, will not be permitted by the court to do so. Competency in general In general, all witnesses are competent to testify unless the court considers that they are prevented from understanding questions put to them, or from giving rational answers to those questions, by reason of tender years, extreme old age, disease (of mind or body), or such similar reason (see s. 127 Tanzania Evidence Act). The question whether a particular witness is competent to testify in court is determined by the court which is seized of the matter. Since all witnesses generally give their evidence on oath or affirmation, and since competency is a pre-condition to the administration of an oath or affirmation, the court must first determine the question whether the witness is competent to give testimony before such oath or affirmation. If, for instance, the person is old, or a lunatic, or a child of tender years, the magistrate will ask him questions to find out the extent of his intellectual capacity and understanding, and whether he has the ability to remember and describe what he has done or perceived or seen on particular occasions. Competency in special cases In certain cases certain people are competent to give testimony provided that certain requirements are met. These include the accused, the dumb, young children, accomplices, husbands or wives and police spies or decoys. The accused An accused person is a competent witness for the defence whether he is charged alone or jointly with any other person. As the law stands, however , he is not compelled to give evidence in his defence at his trial. Dumb witnesses A dumb witness is not incompetent merely because of his being dumb. He can give evidence in some other manner that is intelligible, for example, writing, or signs in open court, and evidence so given is deemed to be oral evidence (see S. 128 TEA). If the witness be both dumb and deaf, he is nevertheless competent if he can give evidence through an interpreter. In such a situation the magistrate will have to be satisfied that the method of interpretation has been tested, and he must further satisfy himself that it is reasonably sophisticated. If he finds the method of interpretation to be crude, he must exclude the evidence (see Hamisi s/o Salum v. Republic (1951) 18 EACA 217). Young children In quite a number of cases the public prosecutor finds himself with witnesses who are young children. The law is that where in any criminal matter any child of tender years called as a witness does not, in the opinion of the court, understand the nature and value of an oath, his evidence may be received, though not given on oath or affirmation, if in the opinion of that court, to be recorded in the proceedings, he is possessed of sufficient intelligence to justify the reception of his evidence, and understands the duty of speaking the truth. But it should be noted that if the testimony of such a child is received without oath or affirmation, it cannot form a basis for a conviction unless it has been corroborated by some other material evidence implicating the accused (see S. 127 (2) TEA. This is a requirement of law. So if you have a case based solely on the testimony of a child of tender years and his evidence is received without oath or affirmation, with no independent and material evidence to corroborate it, the result will be an acquittal. It makes no difference that such evidence is very eloquent. So do not go about calling the magistrate names if he lets off the thief, robber, burglar, arsonist, or rapist. There is nothing he can do about it. 172 Part III Basic Principles of the Law of Evidence It should also be noted that the situation will not be any different if you have the testimony of two or more witnesses who are children of tender years and whose evidence has been received...