Witnesses: Competence, Compellability and Examination
Witnesses: competence, compellability and examination
This domain tests who may give evidence, who can be forced to do so, and how testimony is elicited and tested. Competence concerns capacity to give evidence; compellability concerns liability to be compelled. Examination concerns the form and scope of questioning.
Core rules
- Competence. A witness must understand the questions put and be able to give answers that can be understood. There is no fixed minimum age; children are competent if they meet that test. The oath or affirmation is used where the witness understands the duty to tell the truth; otherwise unsworn evidence may be permitted with safeguards.
- Compellability. Most competent witnesses are compellable. The accused is competent for the defence but not compellable. A spouse or civil partner is generally competent, but compellability is limited to specified offences, such as violence, sexual offences or offences against children.
- Examination-in-chief. Leading questions are generally prohibited. Refreshing memory is allowed in defined circumstances. A witness may be treated as hostile with leave, allowing cross-examination by the party calling them.
- Cross-examination and re-examination. Cross-examination tests accuracy, bias and credit. Re-examination is confined to matters arising in cross-examination.
Worked example
A 9-year-old alleges assault. The judge asks simple questions and concludes she understands the difference between truth and lies. She may give evidence, with special measures such as a screen or video link. If she cannot understand the duty to tell the truth, the court may consider unsworn evidence with a warning. Her parent is competent and, if the offence is one of the specified categories, may be compellable.
Traps
Do not assume a spouse is always compellable. Do not use leading questions in chief. Do not cross-examine beyond the scope of the evidence or use collateral matters to attack credit without a recognised basis. Do not confuse competence with credibility.