Affidavit is a sworn or affirmed written statement of the facts known to a person (Deponent), which is a form of evidence in chief used to supplement, or in some circumstances, replace oral evidence. Affidavits must be drafted so that they comply with rules of evidence of a particular jurisdiction. The corollary of this is that affidavits are normally drawn by legal practitioners on the instructions of a Deponent. Affidavits should be written in the first person and in situations where a Deponent is recalling conversations, the exact words in should be quoted using speech marks. The affidavit must be sworn or affirmed by the Deponent in the presence of a witness, who must be either a Justice of the Peace (JP) or legal practitioner.

Affidavits as a form of evidence in chief has many advantages, particularly in civil cases, in relation to cost and inconvenience minimisation, the promotion of settlement and the prevention of trial by ambush. The effect of this is that parties are able to assist the Court in achieving the overriding purpose of the Civil Procedure Act 2005 (NSW), found in section 56, which is ‘to facilitate that just, quick and cheap resolution of the real issues in proceedings’.

Documents referred to in an affidavit are annexed to it. These documents are called ‘annexures’ and if there are a large number of documents these are bundled into what are known as ‘exhibits’ of which are served along with the affidavit.

Affidavits are served on the parties prior to hearing (‘cards on the table approach’) and are “read” at when the matter goes to trial. It is at this point that the opposing party can object to the contents of an affidavit and the importance of the affidavit being drafted in accordance with the rules of evidence comes to the fore.

The rules of evidence mandate that affidavits must not contain certain information such as, but not limited to, hearsay and opinion. The rule against hearsay, subject to exceptions, is found in section 59 of the Evidence Act 1995 (NSW) and states that ‘evidence of a previous representation made by a person is not admissible to prove the existence of a fact that the person intended to asset by that representation’. For example if a Deponent in an affidavit stated that someone told them that goods were defective when they were sold and delivered (the representation), this conversation prima facie would be inadmissible as evidence. This is because the Deponent is relying on a representation, outside of court, made to them by another party, to prove the existence of a fact (i.e. the goods were defective). There are a number of exceptions to this rule and this evidence may be admissible in civil proceedings on the basis that it is ‘first hand hearsay’ and the person who made the representation ‘saw, heard or otherwise perceived’ the defective goods.

Another common rule that would exclude the whole or part of an affidavit is the opinion rule. Under section 76(1) of the Evidence Act 1995 (NSW), ‘evidence of an opinion is not admissible to prove the existence of a fact about the existence of which the opinion was expressed’. This is to ensure that that only evidence of facts observed are admitted and therefore minimising the risk in misleading a court or jury. The two main exceptions to the opinion rule are found in section 76, the expert evidence exception, which allows for the admissibility of expert opinion evidence that is based on specialised knowledge and section 78, the lay opinion exception, which states that evidence may be admitted if “the opinion is based on what the person saw, heard or otherwise perceived about a matter or event”.