Workplace Investigations Interviewing: best questions and techniques for witnesses

The best witness interviews are structured, impartial and evidence‑led. Plan a question route, set ground rules, use open questions, and probe for specifics if clarity is not provided. Test accounts against documents and data, record exculpatory as well as inculpatory facts, and confirm notes promptly. Align with the Acas Code and reasonable‑adjustment duties.

Introduction

Interviews make or break Workplace Investigations. Done well, they produce clear facts, reduce bias and speed up decisions. Done badly, they cause confusion and undermine fairness and credibility. This guide explains how UK employers can plan and run witness interviews that align with the Acas Code, data‑protection rules and Equality Act principles.

Key takeaways

·        Plan before you ask: define scope, issues and evidence to test; draft non‑leading questions in advance.

·        Start every interview with clear ground rules, confidentiality and the chance to review notes promptly.

·        Use open questions, then funnel to specifics. Try and avoid compound and leading questions.

·        Test accounts against records and other evidence; capture context and exculpatory material.

·        Offer reasonable adjustments so people can participate fairly; handle sensitive topics carefully .

What a good witness interview looks like

A fair interview is proportionate, impartial and well‑documented. The interviewer prepares a question plan, sets a neutral tone, and lets the witness give a free narrative before probing specifics. The interviewer seeks clarity, challenges inconsistencies with care, and confirms an accurate record at the end.

Legal and policy standards that shape interviews

·        Acas Code of Practice, which requires prompt, fair processes including reasonable time to prepare and respond. Interviews should be neutral fact‑finding, not adversarial cross‑examination.

·        Acas guidance: investigations step‑by‑step; planning, interviewing and taking statements; practical tips on neutrality and disclosure.

·        Employment Relations Act 1999, which gives the statutory companion rights and which applies to disciplinary or grievance hearings (not usually investigatory interviews), though many employers allow companions for support.

·        Equality Act 2010 which requires employers to make reasonable adjustments and avoid discriminatory assumptions; handle harassment/discrimination issues sensitively.

·        UK GDPR/DPA 2018 that requires employers to collect only what is necessary, keep data secure, and be transparent about recording, notes and retention.

Interview process: step by step

Scale your approach to the seriousness and sensitivity of the issues. Record decisions and reasons at each step.

1) Plan the interview

·        Define issues and facts to test; list essential documents and data you will refer to.

·        Draft a question route: opening, free narrative, timeline, open questions, detail probes, corroboration, policy context, wrap‑up.

·        Consider reasonable adjustments for disabled employees (for example extra time, remote meeting, breaks, support person).

·        Prepare exhibits with clear labels; decide what to disclose in advance vs show during the interview.

2) Invite and inform

·        Send a neutral invite explaining purpose, topics, confidentiality and data handling.

·        Give reasonable time to prepare; include who will attend and whether a companion is permitted.

·        Explain that accurate notes will be taken and shared for confirmation; set expectations on timing and breaks.

3) Opening ground rules

·        Thank the witness/person and explain roles; confirm consent to note‑taking (or to record).

·        Set expectations: answer in their own words, say if they do not know or cannot remember, and flag if they need a break.

·        Confidentiality: do not discuss the interview with colleagues; explain who may see the notes and why.

4) Eliciting the free narrative

·        “Please tell me, in your own words, what you know about the events of [date/issue]. Start where it makes sense for you.”

·        Listen without interruption; note signposts to follow up (people, dates, systems, locations).

·        Use minimal encouragers (“and then…”, “go on…”) rather than leading.

5) Probing for specifics and testing reliability

·        Timeline: “What happened next?” “Roughly what time?” “Where were you standing?”

·        Detail: “What exactly was said?” “Who else was present?” “What could you see/hear?”

·        Documents/data: “I am showing you [exhibit]. How does this fit with your account?”

·        Consistency: “Earlier you mentioned X but in the email you said Y. Can you help me understand?”

·        Perspective: “What is your understanding of policy/process at that time?” “What options did you consider?”

6) Handling sensitive topics fairly

·        Use sensitive questioning techniques for harassment/discrimination allegations: pace the interview, allow breaks, and avoid blame‑laden phrasing.

·        Offer a support person where appropriate; consider interviewer gender pairing if requested and feasible.

·        Avoid credibility shortcuts based on demeanour; focus on consistency and corroboration.

7) Closing and confirmation

·        “Is there anything we have not covered that you think is important?”

·        Explain next steps and realistic timescales; do not promise outcomes.

·        Send notes promptly for review and correction; record any changes and reasons.

·        Store records securely with restricted access; update your evidence log.

Question bank: open, probing and clarifying questions

Use and adapt these examples to your case. Keep questions open, neutral and single‑barrelled. Avoid assumptions in the wording and signal curiosity, not judgment.

Scene‑setting and context

·        “What do you do in your role and how long have you been in post?”

·        “How do you know the people involved?”

·        “When did you first become aware of the issue?”

Timeline and sequence

·        “Walk me through what happened, step by step.”

·        “What happened just before/after [event]?”

·        “Roughly what time did [event] begin and end?”

Words, actions and context

·        “What exactly was said or done?”

·        “What was the tone/body language?”

·        “Where were you and what could you see/hear?”

People and corroboration

·        “Who else was present and what did they see?”

·        “Who might have messages/emails/calendars relevant to this?”

·        “If I spoke to [X], what do you think they would say?”

Documents and digital evidence

·        “I am showing you [document/chat/CCTV]. Does this help you recall anything further?”

·        “Is there anything in this record you disagree with or would add context to?”

Policy and expectations

·        “What policy or guidance were you aware of at the time?”

·        “How is [process] usually handled in your team?”

·        “What would you have expected a manager/colleague to do in that situation?”

Clarifying uncertainty and memory

·        “If you are not sure, it is fine to say ‘I don’t know’ or ‘I don’t remember’. What is your best recollection?”

·        “How confident are you in that estimate (for example time/distance)?”

·        “Is there anything that might help you recall more accurately?”

Wrapping up

·        “What else should we look at?”

·        “Is there anyone else we should speak to?”

·        “Is there anything you would like to add or correct?”

Common pitfalls (and how to avoid them)

·        Leading or compound questions — ask one open question at a time; let the witness speak.

·        Interrupting the free narrative — listen, then probe; avoid filling silences.

·        Credibility shortcuts based on demeanour — test against records and plausibility instead.

·        Failing to disclose relied‑upon material — fairness requires proportionate disclosure so people can respond.

·        Group interviews — avoid; interview individually to reduce contamination.

·        Recording without purpose or controls — if you record, justify it, inform participants and control access/retention.

Worked examples (anonymised)

Example 1: Harassment on calls — Several team members report belittling comments during video meetings. The interviewer uses open questions, maps a timeline across chat and calendar data, and tests language against transcripts. Consistent patterns are corroborated. The report upholds the complaint and recommends progression to a formal disciplinary hearing,.

Example 2: Stock discrepancies — A warehouse witness initially blames a colleague. Probing reveals gaps in the witness’s own process knowledge. System logs and CCTV contradict key details. The report does not uphold the allegation and recommends training and process fixes.

FAQs

Can we audio‑record interviews? 

Yes. Typed notes reviewed promptly are usually enough. If recording is undertaken, explain why, seek agreement, set access/retention controls and share a summary for corrections.

Do witnesses get companions? 

There is no general statutory right to a companion at investigatory meetings. Companion rights apply at formal disciplinary or grievance hearings, although many employers allow a support person at interviews.

Should we show documents during the interview? 

Yes, where it helps fairness and accuracy. Show relevant extracts, label exhibits clearly, and record what was shown and when.

Can we take anonymous statements? 

Use anonymity only where there are genuine risks. Test reliability, seek corroboration and disclose as much as fairness allows while protecting identities.

How soon should we send notes for confirmation? 

Promptly, ideally within 24 hours. Ask witnesses to correct errors, explain changes and return signed or email‑confirmed copies.

Is it OK to interview remotely? 

Yes. Use secure platforms, confirm identities, manage exhibits in advance, and consider reasonable adjustments. Document any technical issues.

When to get help and next steps

Sensitive or senior‑level cases, or those involving harassment, discrimination or complex digital evidence, benefit from an external interviewer trained in bias‑aware techniques. We can scope, run or review interviews and provide scripts and templates that fit your policies.

Disclaimer: This page provides general information only, based on UK employment law at the date of publication. It is not legal advice.

Our expert employment law solicitors all have many years’ experience advising individuals who are in your position. We will be able to guide you through the process and to help you secure the best possible outcome.

We offer a range of services, so please contact our friendly customer services team to discuss further via hello@kilgannonlaw.co.uk or 07969921491

This article is for information purposes only and is correct at the time of publication. It does not constitute legal advice 31.10.24