What is an expert witness and when would one be involved in my family law case?

In Plain English

An expert witness is someone with special knowledge or skills in a particular field (other than law or accounting) who can help the court understand complex issues in your family law case.

You might need an expert witness if your case involves things like:

  • Figuring out the value of a property or business.
  • Understanding a child's specific needs or developmental issues.
  • Assessing the risk of family violence.

The Federal Circuit and Family Court of Australia (Family Law) Rules 2021 outline the rules for using expert witnesses, including their duty to the court, how their reports are disclosed, and what happens if they change their opinion.

Detailed Explanation

An expert witness is defined in ASA 620 - Using the Work of an Auditor’s Expert - October 2009 as "an individual or organisation possessing expertise in a field other than accounting or auditing, whose work in that field is used by the auditor to assist the auditor in obtaining sufficient appropriate audit evidence." While this definition is in the context of auditing standards, it is applicable to family law.

Here's how expert witnesses are relevant in the context of the provided legislation:

  • When Expert Evidence is Needed: Expertise outside the usual scope of legal knowledge may be required to understand specific aspects of a case. ASA 620 - Using the Work of an Auditor’s Expert - October 2009 provides examples such as valuing assets (financial instruments, property, jewellery, art), actuarial calculations (insurance, employee benefits), estimating reserves (oil, gas), assessing liabilities (environmental), interpreting contracts, and analyzing tax issues.
  • Instruction and Disclosure: If a party intends to use an expert witness, they must provide the expert with Divisions 7.1.4, 7.1.5, and 7.1.6 of the Federal Circuit and Family Court of Australia (Family Law) Rules 2021 to ensure the expert understands their duties and responsibilities (rule 7.13(2)(a)). All instructions to the expert must be in writing and include specific details about the issues, matters for investigation, and full disclosure of relevant information (rule 7.13(3)).
  • Disclosure of Reports: Any expert report obtained for a parenting proceeding must be disclosed to the other parties involved (rule 7.14(1) of the Federal Circuit and Family Court of Australia (Family Law) Rules 2021). This includes any supplementary reports or notices amending the original report (rule 7.14(2)). Legal professional privilege does not apply to these reports (rule 7.14(4)).
  • Failure to Disclose: If a party fails to provide a copy of the expert's report, they cannot use the report or call the expert to give evidence unless the other party and any independent children's lawyer consent, or the court orders otherwise (rule 7.17 of the Federal Circuit and Family Court of Australia (Family Law) Rules 2021).
  • Expert's Duty to the Court: An expert witness has a primary duty to assist the court with matters within their expertise. This duty overrides any obligation to the party instructing or paying them (rule 7.18(2) of the Federal Circuit and Family Court of Australia (Family Law) Rules 2021). The expert must provide objective, unbiased, independent, and impartial opinions (rule 7.18(3)(a)).
  • Content of Expert Reports: An expert report must comply with rules 7.21 and 7.22 of the Federal Circuit and Family Court of Australia (Family Law) Rules 2021, and should include an acknowledgement that the expert has read, understood and complied with the Practice Direction, particulars of the training, study or experience by which the expert has acquired specialised knowledge, identify the questions that the expert was asked to address, set out separately each of the factual findings or assumptions on which the expert’s opinion is based, set out separately from the factual findings or assumptions each of the expert’s opinions, set out the reasons for each of the expert’s opinions, and contain an acknowledgement that the expert’s opinions are based wholly or substantially on the specialised knowledge mentioned in paragraph (c).
  • Changing Opinions: If an expert changes their opinion after preparing a report, they must provide written notice to the instructing party or, if appointed by the court, to the Registry Manager and each party (rule 7.18(5) of the Federal Circuit and Family Court of Australia (Family Law) Rules 2021).
  • Expert's Right to Seek Orders: A single expert witness can request procedural orders from the court to assist in their function, such as clarification of instructions or resolution of fee disputes (rule 7.19 of the Federal Circuit and Family Court of Australia (Family Law) Rules 2021).
  • Evidence in Chief: An expert's evidence in chief consists of their report, any changes to the report, and answers to questions under rule 7.27 of the Federal Circuit and Family Court of Australia (Family Law) Rules 2021 (rule 7.20(1)).
  • Limitations: The court can limit the scope of expert evidence to the named expert and the stated field of expertise (Chunk 74 of the Federal Circuit and Family Court of Australia (Family Law) Rules 2021).