Last reviewed 1 August 2018

Conducting interviews after an accident or incident can be a daunting prospect, not least without a logical and structured framework to orientate the investigation process. Mike Sopp delves into the process by focusing on a particular technique which continues to be the cornerstone of interviewing today.

According to the Health and Safety Executive (HSE), an effective accident or incident investigation requires “a methodical, structured approach to information gathering, collation and analysis”.

The purpose of investigative interviewing is to gather information, ascertain first-hand accounts of an adverse event and collect any other information that would assist the investigation.

To obtain the information, those undertaking interviews must have the necessary skills and be able to apply appropriate interviewing methodologies to achieve successful outcomes.

The purpose of investigation interviews

From a health and safety perspective, accident or incident investigations form an essential part of any health and safety arrangements, thereby meeting the requirements of Regulation 5 of the Management of Health and Safety at Work Regulations 1999.

According to the HSE publication HSG245 Investigating Accidents and Incidents, “an investigation will involve an analysis of all the information available, physical (the scene of the incident), verbal (the accounts of witnesses) and written (risk assessments, procedures, instructions, job guides etc)”.

A key element in the information gathering process is the interviewing of those directly involved in the adverse event and those who may have witnessed the event. Interviews may also have to be held with others who may have relevant information, such as supervisors and managers.

The information gathered through interviews will assist those undertaking the investigation process in drawing conclusions regarding the immediate, underlying and root causes of the event under investigation.

It is essential that the interviews undertaken obtain accurate, relevant and complete information to enable cogent decisions to be taken, not only to prevent future adverse events but (if necessary) to apportion blame in a fair and balanced way if individuals have behaved inappropriately.

HSG245 states that “discovering what happened can involve quite a bit of detective work”. It is from the world of criminal investigation that investigators can utilise best practice in managing and undertaking investigation interviews.

The PEACE framework

In the early 1990s the UK Home Office undertook a review of police interviewing techniques. As a result, the “PEACE” framework for interviewing was introduced and continues to be the cornerstone of interviewing.

The framework has been widely exported and adopted in many disciplines and forms the logical spine of an investigative interview, based upon the following stages.

  • Planning and preparation: organise and review the information you currently have prior to undertaking of the interview.

  • Engage and explain: start the interview and establish the ground rules.

  • Account clarification and challenge: obtain the interviewee’s account, clarify this and, where necessary, challenge it.

  • Closure: summarise and close the interview.

  • Evaluation: ask questions about what was achieved during the interview and how the information arising fits into the whole investigation

The planning and preparation of interviews is essential if the objective of gathering relevant information is to be achieved.

The investigators should discuss at the earliest possible stage the key issues and objectives of the investigation and consequent interviews. Factors that need consideration include:

  • identification of person/s that will require interviewing (eg injured party, witnesses etc)

  • the interviewees’ relationship to the adverse event, the information they can provide and the order in which they should be interviewed

  • the aims and objectives of the interview, based upon the importance of the interviewee’s viewpoint

  • how the information is to be obtained during the interview so as to establish accuracy (eg narrative and questioning)

  • the materials that are already available that may influence the interview (eg personal statements)

  • any practical arrangements and logistics of interviewing (eg location, equipment requirements etc).

Every interview must be prepared with the needs of the investigation in mind, but the interviewers should also take into consideration the needs of the interviewee. Some of those to be interviewed may have been injured in the event, while others who are witnesses may be traumatised by the events. All interviews must also be conducted in line with any requirements of the Equality Act 2010 and any special requirements of the interviewee, such as language difficulties.

It may also be the case that an individual wishes to be accompanied to the interview, eg by a Trades Union Safety Representative.

Having taken into consideration all of the above factors, a plan can be developed that summarises the aims of the interview and provides a framework for questioning. It can detail the topics to be covered and the introduction of other information that may assist the interview process.

The plan should also record who will be the lead interviewer and who is responsible for note-taking. It is important that interviewers understand their respective roles and maintain the role agreed. Two interviewers asking multiple questions in an unstructured manner is unlikely to achieve the interview’s objective.

Conducting the interview

When conducting investigative interviews, the interviewers should always take into account the following principles.

  • Keep an open mind, do not make any pre-conceptions and do not approach any interview with prejudice.

  • Keep an interview “mindset” and focus on the pre-planned aims and objectives of gathering relevant information.

Engaging with interviewees can be challenging, depending upon the circumstances (eg if the individual has knowingly engaged in inappropriate behaviour), but attempts should be made to develop a rapport.

The reasons for the interview should be clearly outlined to the interviewee, including the objectives and the interview process. Where there is a clear policy from the employer on accident/incident investigations and ground rules for interviewing, these should also be explained. It should be confirmed with the interviewee (as well as any representatives) that they fully understand the process to be adopted.

Account clarification, in essence, is about the interviewee providing their narrative account of events of the incident. Interviewees should be allowed to pause so that they can search their memory without interruption, and should be encouraged to continue reporting their account until it is complete.

The investigator should be able to ask questions that challenge and test the credibility of the information being given in a manner that is professional and does not intimidate an interviewee.

Interviewers can then seek clarification of the account by breaking it down into manageable topics and probing further by means of open-ended questions (eg “Tell me…”, “Describe…”, “Explain…”) and specific closed questions (eg “Who did that?” “What did he say?”) until as full a picture as possible of the interviewee’s account has been obtained.

Interviewers can also choose to use closed question that require a definitive answer or probing questions that test the strength of the interviewee’s account or challenge any inconsistencies identified during the interview. However, these questions should be inquisitive rather than interrogative in nature.

Leading questions should be avoided, while questions requiring multiple responses can be confusing.

Questions should be as short and simple as possible. They should not contain jargon or other language which the interviewee may not understand.

Closure of the interview includes checking that there are no further questions and accurately summarising what the interviewee has said, taking account of any clarification that the interviewee wishes to make. Any questions the interviewee asks should be answered where possible. It is also worth explaining to the interviewee what shall happen after the interview process.

After the interview

Following an interview, the interviewers need to evaluate what has been said with a view to determining whether any further action is necessary and how the interviewee’s account fits in with the rest of the investigation. Questions to consider include the following.

  • Is there additional evidence arising from the interview that needs to be considered?

  • Was the account consistent with the existing evidence?

  • Do we need to make any further enquiries or undertake additional interviews?

  • Do we have sufficient information to make cogent conclusions as to the causes of the adverse event?

  • Is there sufficient information to make recommendations for improve safety and/or disciplinary action?


Good preparation is the key to an effective investigation interview based upon the desired outcomes of the investigation.

Selecting and using the most appropriate types of questions will enable the most appropriate information to be gleaned from the interviewee. Open questions are best but closed and inquisitive questions can also be useful.

Body language when conducting the interview should be considered in terms of open posture (eg not folding arms), suitable eye contact and appropriate affirmative facial expressions and gestures, such as nodding.

Interviewers should also be aware of how to manage reluctant interviewees. This can be detected through body language, hesitation in responding, etc. The interviewer should try to ascertain the reasons behind this (eg fear of reprisals) and seek to put the individual at ease (eg by anonymised statements).

Further information