Expert witness work is one of the least understood parts of what a clinical and forensic psychologist does, largely because it happens outside the therapy room entirely — and it runs on different rules from clinical work, which surprises people who assume it’s just an assessment with extra paperwork.
The first and most important difference is who the client is. In a court-instructed assessment, my duty is to the court, not to the person being assessed — even when I’ve been instructed by their solicitor. That’s a formal, ethical distinction, not a technicality: the report has to be independent and balanced, setting out what the evidence supports rather than what would help one side’s case. Anyone I assess is told this plainly before we start, because informed consent matters just as much here as it does in therapeutic work, even though the purpose and the audience for the outcome are completely different.
The assessment itself typically draws on several sources rather than one conversation: a structured clinical interview, standardised psychometric measures relevant to the referral question — capacity, risk, the psychological impact of specific events — and, where available, other case documentation, so the resulting opinion isn’t formed on self-report alone. What the referral question actually is matters enormously; an assessment of litigation capacity looks nothing like an assessment of psychological harm following an incident, and the methods, measures, and structure of the report are shaped entirely around the specific question being asked.
The final report follows a formal structure set out in the relevant Civil or Family Procedure Rules, ending in a statement of truth and a declaration that the expert understands their overriding duty to the court. It has to be written so that someone without clinical training — a judge, a jury, opposing counsel — can follow the reasoning from evidence to conclusion, which is a genuinely different discipline from writing clinical case notes, and one that’s easy to underestimate until you’ve had to defend a report under cross-examination.
I undertake this work across criminal, family, and civil cases. If you’re a solicitor considering instruction, or want to understand what an assessment would involve before agreeing to one, I’m happy to talk through the process.
