Investigations for discipline and grievance: step by step

Step 4: If there are witnesses

Witnesses can give important evidence that might help decide the outcome of a disciplinary or grievance case.

If there’s anyone with information about the discipline or grievance issue (a ‘witness’), the person investigating can ask them to write it down (a ‘witness statement’).

The person investigating can also have a meeting with a witness to ask them what they know or saw. Someone should take notes during the meeting. At the end of the meeting, the witness should sign the notes and these can also form a witness statement.

    Taking a witness statement

    The person investigating might decide a witness can give a statement without having a meeting, if the witness:

    • is not an employee, for example is a customer or client
    • only needs to give very simple information
    • is ill and cannot come to an investigation meeting

    The person investigating should ask the witness to write:

    • answers to specific questions, where necessary
    • their name and, where applicable, job title
    • the date, place and time of any relevant issues
    • what they saw, heard or know
    • the reason why they were able to see, hear or know about the issues
    • the date and time of writing their statement
    • their signature

    The witness should have reasonable time to give the statement.

    Talking to a large number of witnesses

    If a large number of people witnessed the same incident, the person investigating should:

    • talk to some of the witnesses
    • check whether they’re broadly saying the same thing

    The person investigating does not have to talk to all witnesses, unless either of the following apply:

    • they feel they’re not getting enough information
    • there are significant differences in what the witnesses say

    Taking records

    The person investigating can make audio recordings of interviews or assign a person to take notes, depending on:

    • what is most appropriate or possible
    • what your organisation’s policy or rules allow
    • if the person being interviewed agrees

    For more on recording investigation meetings, see the Acas guide to conducting workplace investigations (PDF, 379KB, 36 pages).

    Keeping it confidential

    When getting information from a witness, it’s a good idea to get their consent to be able to share it if necessary. For example, in case other people working on the investigation need to look at the information.

    If someone believes they’ve been named in a report, they have the right to see any parts that:

    • have information about them
    • depended on information they gave

    They should not be allowed to see private information about other people.

    The employer should keep investigation reports for a while, in case there are any questions in the future. How long they keep reports might be set out in a workplace policy.

    If the report includes people’s details, the employer should store it securely and only allow access when necessary. Anyone who has access needs to be aware of data protection law (GDPR).

    The report should be securely disposed of once it’s no longer needed or is out of date, for example it could be shredded.

    Find out more about data protection on the Information Commissioner’s Office (ICO) website.

    More guidance on carrying out investigations

    See the Acas guide to conducting workplace investigations (PDF, 379KB, 36 pages) for more on:

    • interviewing witnesses
    • if a witness refuses to give a statement