Serial Deception: Second Test Confirms Repeated Infidelity
The first test was in August. It came back deception-indicated. Steven admitted, said it was over, and Karen chose to try to repair what was left. In November she noticed the signs again — different, but familiar. She booked a second test. It came back deception-indicated again. This is the only case study that documents both.
Important Privacy & Sensitivity Notice
Anonymisation: All names and identifying details have been fully anonymised. "Karen" and "Steven" are not the subjects' real names.
Purpose: This case study exists because the two-test scenario — where a deception-indicated result is followed by an attempt at reconciliation, and then a second test — is a situation we see and one that is rarely documented. Understanding what the second test involves, why it differs from the first, and what the combined findings establish is useful for people considering whether to test a partner who has previously admitted infidelity.
Consent: Steven provided full informed written consent for both sessions. Consent for each test is obtained independently.
The First Test — August 2025
"Karen" (anonymised, mid-thirties, South Yorkshire) had been in a relationship with "Steven" for six years. The first test was booked in August 2025 after several months of behaviour changes she had been unable to dismiss or explain. Steven agreed to be tested.
The August test returned deception-indicated results across three of four probe sets. The probability scores ranged from 88% to 93%. When Karen was given the verbal result, Steven admitted the infidelity the same day. He described it as a single involvement that had ended. He said it would not happen again. Karen described the following weeks as the hardest of the relationship — and also the most honest conversations they had ever had.
She chose to stay. Not without difficulty. Not without awareness of the risk. But with a conscious decision that six years and a genuine relationship was worth one attempt at repair.
The reconciliation period — August to November
What Karen was trying to do — and what she observed
Karen describes the four months after the first test as an attempt in good faith. Steven had admitted the infidelity and named the involvement. He had, in her account, been more present and more communicative in the weeks that followed than he had been for months before the test. She described herself as cautiously optimistic at the end of September.
By late October the familiar patterns had started to return. Not identical to what she had seen before the first test — she was looking for those and did not find them in the same form. But the same categories: availability that didn't add up, phone habits that changed, a quality of distraction she had learned to read. Different enough that she tried to dismiss it as post-discovery anxiety. Similar enough that she could not.
She contacted us in November. She did not present this as a decision she was uncertain about. She was clear: she needed to know whether the infidelity had continued or resumed, and she needed the documented answer rather than her suspicion. She was not hoping to be wrong this time. She was hoping to be equipped.
Test 1 vs Test 2 — What Changed
Initial infidelity investigation
Probe design built around the specific person and contexts Karen had identified from behaviour changes over the preceding months. Probability scores 88–93%. Same-day admission by Steven. Infidelity confirmed as a single involvement, described as ended.
Ongoing or resumed infidelity investigation
Probe design rebuilt around new contexts and updated circumstances. Explicitly tested whether the involvement admitted in August had ended as stated, and whether new involvement had begun. Probability scores 91–97%. Broader and deeper deception-indicated result than the first test.
Why the second test required a different probe design
A second test is not a repeat of the first. The probe stimuli for the first test were built around the specific person and circumstances of the initial suspected infidelity. Four months later, those specific stimuli were less useful — Steven already knew the details that had been tested, and the question the second test needed to answer was different: had the involvement he admitted in August continued, and had new involvement begun?
The second probe design was built around three distinct questions:
- Ongoing involvement: Whether the specific involvement admitted in August had ended as stated, or whether neurological memory consistent with continued contact was present.
- New involvement: Whether new contexts Karen had identified in the October–November period corresponded to neurological recognition consistent with concealed intimate activity.
- The pattern: Whether the scale of the deception was limited to what had been admitted, or whether the probe responses were consistent with a wider pattern than Steven had disclosed after the first test.
The Second Test — December 2025
Steven agreed to the second test. Karen described his agreement as different from the first — less immediate, more considered. He did not refuse. He said that if she needed it, he would do it. Karen noted, but did not say to him, that his hesitation told her something the first test had not needed to tell her.
Probe Set 1 — August involvement: ongoing or ended?
Stimuli built around specific details of the involvement admitted in August, testing whether Steven's neurological memory was consistent with the involvement having ended at the point he described — or whether recognition responses consistent with continued contact after that date were present. The test directly addressed the factual accuracy of Steven's August admission.
Probe Set 2 — New contexts: October and November
Stimuli built around the specific contexts and circumstances Karen had identified in the October–November period — the new pattern of behaviour that had prompted the second booking. Tested whether these corresponded to neurological recognition consistent with concealed intimate activity or with innocent explanations.
Probe Set 3 — New individual recognition
Stimuli built around specific individuals Karen had identified as potential connections in the new pattern — not the same individual as the August involvement. Tested whether Steven held neurological familiarity with these individuals consistent with intimate involvement beyond ordinary social acquaintance.
Probe Set 4 — Scope of the deception: wider than admitted?
Stimuli testing whether the scope of the infidelity was consistent with what had been admitted after the first test, or whether recognition responses indicated a pattern broader and longer-standing than the single involvement he had described. The most significant probe set in the second test.
Pre-session briefing
Steven was briefed that the second test concerned Karen's concerns about the period since August. He was told the probe design covered both the August involvement and the new concerns from October–November. He consented. He was, in the examiner's assessment, less relaxed than at the first appointment.
Baseline calibration
Standard baseline. Steven's baseline was well-defined and consistent — allowing the probe results to be assessed clearly against his individual neurological parameters.
Four probe set sessions (85 minutes)
All four probe sets delivered. Steven's session was longer than the first test because the second probe design covered more ground across four distinct areas rather than the three probe sets used in August.
Verbal result — deception-indicated on all four probe sets
Karen received the result alone first, as she had requested. The result was more comprehensive than the first test — deception-indicated across all four probe sets rather than three. When Steven was informed, he admitted that the August involvement had continued and that a new involvement had begun in October.
What the second test established that the first could not
- The August involvement had not ended at the point Steven claimed — it had continued through the reconciliation period
- A separate new involvement had begun in October, during the period Karen had been trying to repair the relationship in good faith
- The scope of the deception was wider than the single involvement admitted after the first test — Probe Set 4 returned the highest probability score of either test at 97%
- Steven's hesitation before agreeing to the second test was, in retrospect, consistent with knowing the scope the second test was designed to cover
- The first test had identified what Steven was prepared to admit when confronted. The second test identified what he had not admitted.
Key Findings Across Both Tests
- Test 1 (August) returned deception-indicated on three of four probe sets, prompting admission of a single involvement described as ended. Test 2 (December) returned deception-indicated on all four probe sets, establishing that the first admission was partial and that infidelity had continued and expanded.
- The second test's highest probability score — 97% on Probe Set 4 (wider scope) — was higher than any single score recorded in the first test, consistent with the second test having identified a pattern more extensive than the first disclosure had revealed.
- Steven's second admission confirmed both the continuation of the August involvement and the commencement of a new one in October — validating all four second-test probe sets.
- The second test was a different investigation from the first: different probe design, different questions, different evidential scope. Prior knowledge of the first session produced no advantage in the second because the stimuli tested different and updated content.
- Karen ended the relationship after the second test. She described having the second written report as important — not because she needed further conviction, but because it documented the full scope of what had happened rather than only the portion disclosed after the first test.
Outcome
Karen ended the relationship the week after the second test. She described the decision as the clearest she had made in years — not easy, but unambiguous. The second written report gave her documentation not just of the second test's findings but, in combination with the first, of the full pattern: the original infidelity, the partial admission, the continuation during the reconciliation period, and the new involvement.
She had, she said, given the relationship a genuine second chance and had the documented evidence of what that second chance had been used for. That evidence was not something she had produced through accusation or suspicion. It was documented by two independent neurological investigations that Steven had consented to on both occasions.
She also said something that we are including here because it is relevant to anyone in the same situation: the four months between the two tests had not been wasted. She had given the relationship the best honest attempt she was capable of giving it. The second test confirmed that the relationship had not met that attempt with equivalent honesty. The decision to leave, documented on that basis, was one she felt she could not be argued out of — not by Steven, not by anyone, and not by her own future doubt.
What This Case Demonstrates
A first admission after deception-indicated may be partial, not complete
When a deception-indicated result prompts an admission, the admission is typically of what the subject calculates is necessary given the evidence presented. In this case, Steven admitted a single involvement after the first test — the minimum that the first test's findings required him to acknowledge. The second test established that the full scope of the deception was wider. The first admission had been a managed disclosure rather than a complete one.
The second test is a different investigation, not a repeat
Prior familiarity with the P300 EEG process produces no advantage in a second session. The probe stimuli are different, the questions being tested are different, and the neurological responses being measured are involuntary and cannot be managed through preparation. Steven's agreement to the second test was the same act of consent as the first — and produced results that were, if anything, more comprehensive than the first.
Documentation of the full pattern has value beyond the final decision
Karen ended the relationship after the second test. She described the combined documentation — both written reports — as important not for the decision itself, which she had already made, but for its permanence. Two independent, documented, neurological investigations conducted four months apart, both returning deception-indicated. That is a factual record she could not be argued out of, and that neither Steven's subsequent account nor her own future doubt could revise. She knew what she knew, and she had the papers to prove it.
Partner Was Deception-Indicated Before — And You're Suspicious Again?
A second test addresses a different question from the first. If you have reason to believe infidelity has continued or resumed, we can design a second investigation around the specific new circumstances. Same-day verbal result. Written report within 24 hours.