Expert evidence in children proceedings: principles for practice and better outcomes

Professionals working across family law, whether in local authority social care, legal teams, or independent practice, regularly engage with expert evidence in proceedings. In cases where decisions carry lifelong consequences for children, the proper use, scrutiny, and understanding of expert evidence is not simply procedural. It is fundamental to achieving fair and welfare-focused outcomes. Many issues can crop up when it comes to the instruction of an expert, how to do so as well as how to challenge a report.

Independence and impartiality: the foundation

At the heart of expert evidence lies the principle of independence. Experts owe their duty to the court, not to the party instructing them. This is a well-established principle. Professionals working within the legal sector must therefore be alert not only to the credentials of an expert, but to the manner in which their evidence is developed and presented. Clear instructions, transparency in methodology, and adherence to the expert’s duty are all essential safeguards. The starting point for any instruction is to consider the Family Procedure Rules 2010.

Seeking permission: necessity, not convenience

Under Part 25 of the Family Procedure Rules 2010, expert evidence is permitted where it is “necessary” to assist the court (see R25.4). This is a deliberate threshold, reflecting the need to avoid delay and ensure proceedings remain focused on the child’s welfare.

In practice, this requires careful and disciplined thinking. Applications to instruct experts should not be routine or speculative. Instead, professionals seeking to make an application should ask:

• What issue cannot be resolved without expert input?
• Is this issue central to the welfare decision?
• Is there existing evidence that already addresses it?

A well-framed application will identify the specific question the expert is being asked to answer, explain why it falls outside the expertise of the court or social care professionals, and demonstrate proportionality.

Equally important is the selection of the expert. Ensuring the right expertise is brought into the case, whether medical, psychological, or otherwise is a critical question. Mismatches between the issue and the expert’s specialism can lead to evidence being given little weight.

Reliability and weight: recognising potential weaknesses

Expert evidence can be challenged, and there are various ways in which this can be done. Courts are increasingly attentive to factors that may undermine reliability, including:

• Insufficient factual foundation;
• Failure to engage with relevant alternative explanations;
• Lack of clarity in reasoning; and
• Departures from established professional standards.

For those working in local authorities and legal practice, identifying these issues early is crucial. Uncritical acceptance of expert conclusions can distort safeguarding decisions, while failure to challenge weak evidence may result in outcomes that do not properly reflect the child’s needs or risks. Of course, much is fact dependent, and the real question relates to what the expert evidence was there to address.

Importantly, challenging expert evidence for example via cross examination is not about undermining experts, but about ensuring that their evidence is properly tested and understood and that weight to such evidence can be considered.

Remember the focus: welfare

Ultimately, the framework governing expert evidence exists in the context of the welfare of the child. Delays caused by unnecessary expert involvement, or decisions influenced by flawed evidence, can have profound consequences.

A careful, principled approach, grounded in necessity, independence, and critical evaluation ensures that expert evidence fulfils its proper role: assisting the court and professionals to make informed, balanced, and just decisions. 

Mani Singh Basi is a barrister at 4PB. He is the author of the recently published A Practical Guide to Expert Evidence in Proceedings Concerning Children, which provides a detailed, practice-focused exploration of these issues, drawing together case law, procedural rules, and strategic considerations for those working in this field.