desirable to use against one prisoner the evidence of another
who is being tried with him, the latter should be released, or a
separate verdict of not guilty taken against him. A prisoner so
giving evidence is popularly said to turn king’s evidence. It
follows that, subject to what has been said above as to persons
tried together, the evidence of an accomplice is admissible
against his principal, and vice versa. The evidence of an accomplice
is, however, always received with great jealousy and caution.
A conviction on the unsupported testimony of an accomplice
may, in some cases, be strictly legal, but the practice is to require
it to be confirmed by unimpeachable testimony in some material
part, and more especially as to his identification of the person or
persons against whom his evidence may be received. The wife
of a person charged is now a competent witness, but, except in
certain special cases, she can only give evidence for the defence,
and can only give evidence if her husband applies that she should
do so. The special cases in which a wife can be called as a
witness either for the prosecution or for the defence, and without
the consent of the person charged, are cases arising under particular
enactments scheduled to the act of 1898, and relating
mainly to offences against wives and children, and cases in which
the wife is by common law a competent witness against her
husband, i.e. where the proceeding is against the husband for
bodily injury or violence inflicted on his wife. The rule of exclusion
extends only to a lawful wife. There is no ground for
supposing that the wife of a prosecutor is an incompetent witness.
A witness is incompetent if, in the opinion of the court, he is
prevented by extreme youth, disease affecting his mind, or any
other cause of the same kind, from recollecting the matter on
which he is to testify, from understanding the questions put to him,
from giving rational answers to those questions, or from knowing
that he ought to speak the truth. A witness unable to speak
or hear is not incompetent, but may give his evidence by writing
or by signs, or in any other manner in which he can make it intelligible.
The particular form of the religious belief of a witness,
or his want of religious belief, does not affect his competency.
This ground of incompetency has now been finally removed by the
Oaths Act 1888. It will be seen that the effect of the successive
enactments which have gradually removed the disqualifications
attaching to various classes of witnesses has been to draw a
distinction between the competency of a witness and his credibility.
No person is disqualified on moral or religious grounds, but his
character may be such as to throw grave doubts on the value
of his evidence. No relationship, except to a limited extent that
of husband and wife, excludes from giving evidence. The parent
may be examined on the trial of the child, the child on that of
the parent, master for or against servant, and servant for or
against master. The relationship of the witness to the prosecutor
or the prisoner in such cases may affect the credibility of
the witness, but does not exclude his evidence.
3. Privilege.—It does not follow that, because a person is competent to give evidence, he can therefore be compelled to do so.
No one, except a person charged with an offence when giving evidence on his own application, and as to the offence wherewith he is charged, is bound to answer a question if the answer would, in the opinion of the court, have a tendency to expose the witness, or the wife or husband of the witness, to any criminal charge, penalty, or forfeiture, which the court regards as reasonably likely to be preferred or sued for. Accordingly, an accomplice cannot be examined without his consent, but if an accomplice who has come forward to give evidence on a promise of pardon, or favourable consideration, refuses to give full and fair information, he renders himself liable to be convicted on his own confession. However, even accomplices in such circumstances are not required to answer on their cross-examination as to other offences. Where, under the new law, a person charged with an offence offers himself as a witness, he may be asked any question in cross-examination, notwithstanding that it would tend to criminate him as to the offence charged. But he may not be asked, and if he is asked must not be required to answer, any question tending to show that he has committed, or been convicted of, or been charged with, any other offence, or is of bad character, unless:—
(i.) The proof that he has committed, or been convicted of, the other offence is admissible evidence to show that he is guilty of the offence with which he is then charged; or,
(ii.) He has personally, or by his advocate, asked questions of the witnesses for the prosecution, with a view to establish his own good character, or has given evidence of his good character, or the nature or conduct of the defence is such as to involve imputations on the character of the prosecutor or the witnesses for the prosecution; or,
(iii.) He has given evidence against any other person charged with the same offence.
He may not be asked questions tending to criminate his wife.
The privilege as to criminating answers does not cover answers merely tending to establish a civil liability. No one is excused from answering a question or producing a document only because the answer or document may establish or tend to establish that he owes a debt, or is otherwise liable to any civil proceeding. It is a privilege for the protection of the witness, and therefore may be waived by him. But there are other privileges which cannot be so waived. Thus, on grounds of public policy, no one can be compelled, or is allowed, to give evidence relating to any affairs of state, or as to official communications between public officers upon public affairs, except with the consent of the head of the department concerned, and this consent is refused if the production of the information asked for is considered detrimental to the public service.
Again, in cases in which the government is immediately concerned, no witness can be compelled to answer any question the answer to which would tend to discover the names of persons by or to whom information was given as to the commission of offences. It is, as a rule, for the court to decide whether the permission of any such question would or would not, under the circumstances of the particular case, be injurious to the administration of justice.
A husband is not compellable to disclose any communication made to him by his wife during the marriage; and a wife is not compellable to disclose any communication made to her by her husband during the marriage.
A legal adviser is not permitted, whether during or after the termination of his employment as such, unless with his client’s express consent, to disclose any communication, oral or documentary, made to him as such legal adviser, by or on behalf of his client, during, in the course of, and for the purpose of his employment, or to disclose any advice given by him to his client during, in the course of, and for the purpose of such employment. But this protection does not extend to—
(a) Any such communication if made in furtherance of any criminal purpose; nor
(b) Any fact observed by a legal adviser in the course of his employment as such, showing that any crime or fraud has been committed since the commencement of his employment, whether his attention was directed to such fact by or on behalf of his client or not; nor
(c) Any fact with which the legal adviser became acquainted otherwise than in his character as such.
Medical men and clergymen are not privileged from the disclosure of communications made to them in professional confidence, but it is not usual to press for the disclosures of communications made to clergymen.
4. Oaths.—A witness must give his evidence under the sanction of an oath, or of what is equivalent to an oath, that is to say, of a solemn promise to speak the truth. The ordinary form of oath is adapted to Christians, but a person belonging to a non-Christian religion may be sworn in any form prescribed or recognized by the custom of his religion. (See the article Oath.)
5. Publicity.—The evidence of a witness at a trial must, as a general rule, be given in open court in the course of the trial. The secrecy which was such a characteristic feature of the “inquisition” procedure is abhorrent to English law, and, even where publicity conflicts with decency, English courts are very reluctant to dispense with or relax the safeguards for justice which publicity involves.
