Two Siblings, One Accusation
A Family Dispute Lie Detector Case Study

Names, places and identifying details in this case study have been changed to protect client confidentiality, and some circumstances are drawn together from more than one comparable case. What has not been changed is how the test was structured, why it was structured that way, and what the process looked like from first phone call to written result - because that is the part a reader deciding whether to book can actually learn from.

Fourteen Thousand Pounds and Two Years of Silence

When the family's mother moved into residential care, her two adult children discovered that around 14,000 pounds had been withdrawn from her savings over the preceding three years - cash withdrawals, made with her bank card, during a period when both siblings had helped with her shopping, bills and appointments. Each sibling was certain the other had taken it. By the time the sister rang us, the two had not spoken except through solicitors for almost two years, the mother's care was being coordinated through an exhausted aunt, and a police report had gone nowhere for the reason these cases usually do: shared legitimate access and no way to attribute individual withdrawals.

She was not ringing to catch her brother. Her words: "I want to be able to sit in the same room as him at Mum's funeral, whenever that comes, and that cannot happen while he thinks I am a thief." A family case is rarely about the money by the time it reaches us.

Identical Scope, Both Siblings, Results Shared Together

A one-sided test in a two-sided accusation invites a predictable failure: whoever did not book it calls it rigged. So the proposal put to both siblings - through the aunt, initially, as the only channel both trusted - was symmetrical. The same examiner, the same protocol, the same single-issue questions about the specific withdrawals, and both written results shared with the wider family simultaneously. Neither would learn their own result before the other. The question design guide explains the discipline; the symmetry was what got the brother to yes.

Both also agreed, in writing beforehand, on what the outcomes would mean: two passes would be treated by the whole family as closing the accusation between the siblings for good, whatever unanswered questions remained about the money itself. That clause did more work than any other part of the process.

Two Appointments, a Fortnight Apart

The sister tested first, at a discreet local venue; the brother a fortnight later on identical scope. The protocol measured recognition of the specific details - amounts, cash machines, dates - that only the person who made the withdrawals would recognise, rather than measuring stress, which in a family case is universal and means nothing. Our guide to nerves and false positives covers why that distinction matters most in exactly these emotionally loaded cases.

Both siblings passed on every agreed question.

An Answer Neither Expected, and a Repaired Family

Two passes forced the question neither sibling had seriously asked in two years: if not them, who? With the accusation between them dissolved, the family re-examined the timeline together and identified a third party with periodic access to the mother's home and, it turned out, a history of money trouble nobody had known about. That matter was passed back to the police with the new focus. It has not, at the time of writing, produced a prosecution - and the family, notably, describe the process as a success anyway.

Because the thing they had actually lost was not the 14,000 pounds. The siblings resumed speaking the week the results were shared; the brother now handles the care-home paperwork the aunt had been carrying alone. A lie detector test cannot recover money and it cannot prosecute anyone. What it did here was subtract a false accusation that had cost a family two years - which is, more often than people expect, the real product. The accuracy guide is the right next read for anyone weighing whether a result would carry that weight in their own family.

Family Dispute Lie Detector Testing: FAQs

Short answers to the questions people in this situation ask next.

Related Guides and Case Studies

Before you book: how accurate is a polygraph test and what a lie detector test costs in the UK. Browse all of them on the case studies index. More case studies: clearing a false accusation of cheating and a workplace theft investigation.