Rules about giving evidence

When you are giving evidence, the lawyers and the judge can object to certain things you are asked or try to say. This is because there are legal rules about what evidence you can give.

In criminal and civil cases, the court can only decide on the issue before it based on the evidence given in the case.

The judge can interrupt you and ask you to stop if one of the rules of evidence is being broken.

It is also a criminal offence to give evidence which you know is false. This is known as perjury.

Personal knowledge

As a witness, you can only give evidence about facts within your own personal knowledge. You cannot testify about what somebody else saw or heard.

Opinion

You cannot normally give evidence about your opinion. Your testimony must be a statement of the facts. It cannot contain any assumptions you have made, or conclusions you have drawn from those facts.

The exception to this rule is the expert witness who can give evidence that is their opinion based on their expert knowledge.

Hearsay

You cannot give evidence about what someone else said. This is known as the hearsay rule.

For example, you cannot give evidence that your mother told you she saw the accused grab your purse. In that case, your mother should give evidence in court to say that she saw the accused grab your purse.

Statements you have made

You cannot give evidence about previous statements you have made.

For example, you cannot give evidence that you told your friend that the accused grabbed your purse. You can only give evidence about the actual incident.

However, if you are giving evidence as a victim of rape, you can introduce evidence that you made a complaint after the rape.

Telling the truth

Your main duty as a witness is to tell the court the truth. If you knowingly make a false statement under oath, you may have committed the crime of "perjury" and you can be prosecuted (read more below).

If you are giving evidence (either during the examination or the cross-examination), and you do not want to answer a question, you must let the judge know that you are not prepared to answer the question and why.

The judge will only allow you to refuse to answer a question in a very few circumstances if it is relevant to the case. The right to refuse is known as a privilege.

Privilege applies in the following situations:

• Privilege against self-incrimination: This means you can refuse to answer questions or hand over documents because they may expose you to criminal prosecution.
• Legal professional privilege: This means you and your legal advisor cannot be forced to disclose communications between you. Any communication that is made in contemplation of litigation is also privileged. For example, if you are considering taking a court case, then communication about that is protected.
• Sacerdotal privilege: This means that priests can refuse to answer questions about what was said in the confessional. Similarly, communications with a counsellor can also be privileged.

If you refuse to answer a question, the judge will decide if you must answer the question. If the judge decides that you cannot rely on a "privilege", then you must answer the question. If you fail to do so, you will be in contempt of court and you can be imprisoned.

It is a criminal offence to give evidence that you know is false under oath (perjury). This applies to:

• Evidence that you give in court, or
• Any evidence that you give in an affidavit (a sworn written statement from you) or anything in a statutory declaration.

It is also a criminal offence to force, persuade or induce another person to give false evidence (commit perjury).

A person who commits perjury can be fined up to €100,000 and/or imprisoned for up to 10 years.

You should get legal advice for more detailed information. Read about how to find a solicitor.

You can find more about evidence and criminal trials.

Read more about the types of witnesses who give evidence.

The Courts Service has information on what and who to expect in court and a video to prepare for your civil court hearing.