The report

Types of report

There are likely to be two main types of expert report in prosecution proceedings:

  • one dealing with clearly measurable matters (such as the results of analysis and tests);
  • the other with broader matters of opinion, such as safe systems of work.

The first can best be described as a laboratory report and the second might be termed a consultant's report, although some reports may include elements of both.

In certain circumstances, particularly where advice is sought but prosecution is not envisaged, specialist inspectors might prepare a short summary report. However, where an investigation is likely to lead to enforcement action, a more detailed report and, where necessary, a formal witness statement will be required. Experts may either produce a full report, exhibited in a brief covering statement on form LPS 9 or, except in Scotland, if the information is shorter (such as a laboratory report), they may provide all the information in the statement itself, on form LP 70. In Scotland a separate report is always required as this can be lodged as a production. Statements are not used as productions in Scottish courts. Whilst both approaches are valid, it is recommended that specialists draft reports in such a way as to allow them to be formally exhibited to a statement if required; this will also make it easier to update the report if further information is received.

Reports should therefore be stand-alone documents. Both reports and statements should be double-spaced.

Contents of the report

All reports should begin with the expert's name, official address, occupation, relevant academic and professional qualifications, accreditations including membership of professional institutions, career history, relevant experience, the range and extent of his/her expertise and any limitations upon the expertise. Detailed CVs are increasingly being asked for and it may be preferable to provide this in an appendix.

The report should include:

  • A statement setting out the substance of all the instructions received (written or oral), questions upon which an opinion is sought, the materials provided and considered, and the documents, statements, evidence, information or assumptions which are material to the opinions expressed or upon which those opinions are based. Where necessary, the report should give the current state of the inquiry and the areas where further information would be needed to reach a final view;
  • Information on who has carried out measurements, examinations, tests etc, the methodology used and whether or not such measurements etc were carried out under the expert's supervision;
  • Where there is a range of opinion in the matters dealt with in the report, a summary of the range of opinion and the reasons for the opinion given. Any material facts or matters that detract from the expert's opinions, and any points which should fairly be made against any opinions expressed in the report, should also be set out;
  • Relevant extracts of literature or any other material which the expert has relied on in reaching his/her decision or which might assist the court (see also 'Extrinsic material' below)
  • A statement to the effect that the expert has complied with his/her duty to the court to provide independent assistance by way of objective and unbiased opinion and an acknowledgment that the expert will inform all parties and, where appropriate, the court in the event that his/her opinion changes on any material issue.

The expert's final opinion should be based on as much information as possible and can then deal with any question which may arise subsequently. The report should be signed by the expert before it is sent to the investigating inspector for inclusion in the completed Prosecution Report for the procurator fiscal. For guidance on draft reports, see below.

If, on exchange of experts' reports, which in Scotland is managed by the procurator fiscal, matters arise that require a further or supplemental report, the above guidelines should once again be followed.


The opinion of an expert is admissible on matters that are outside the ordinary knowledge of the court but within his/her expertise. The expert should therefore make it clear when any matter falls outside his/her expertise.

If more than one expert is to be called by the prosecution, it is important to avoid too much overlap in their reports, except in Scotland there may be a need for corroboration. Each expert should indicate where his/her expertise ends and should not go 'out on a limb', as s/he will be cross-examined on the report if the case is defended.

The prosecution must establish its case beyond reasonable doubt, but it can still do so despite a doubt which an expert might have to accept. This has been expressed as follows:

the available data may be inadequate to prove scientifically that the alternative hypothesis is false, so the scientific witness will answer "No, I cannot exclude it," though the effect of his evidence as a whole can be expressed in terms such as "But for all practical purposes (including the jury's) it is so unlikely that it can safely be ignored".

The expert should explain the operation and shortcomings in terms which a layman can understand, and it may be useful for him/her to use headings.

If the expert has dealt with similar subject matter elsewhere where better standards were achieved, s/he can make comparisons. If s/he has been involved with the defendant(s) and advised, his/her previous advice may be relevant to foreseeability and his/her credibility.

The expert should not, however, ignore any evidence or conclusions that are unfavourable to the prosecution. These should be discussed with the prosecuting inspector and lawyer (including a solicitor agent and counsel, if instructed, or procurator fiscal) and the expert should point out any potential problems. S/he should not omit factors from his/her report that do not support his/her opinion; s/he should deal with these and explain how s/he has taken them into account. The report should not mislead by omission.

Expected defences

The expert should be asked to deal with any expected defence and evaluate any defence documents. The statements may include some from middle management explaining the system and admitting shortcomings, and statements taken using section 20 powers from directors. Frequently, the prosecution will not rely upon these statements and so the expert will not be able to refer to them, but s/he should instead indicate the kind of system and safeguards s/he would expect. Although the prosecution expert will give evidence first, his/her report is the basis for advance rebuttal of expected.

Medical confidentiality

The relationship of doctor and patient is one to which a duty of confidentiality attaches in order to ensure that patients make full and frank disclosure when seeking diagnosis and treatment. A patient has a right to expect that his/her doctor will not pass on any personal information which s/he acquires in the course of his/her professional duties, unless the patient gives consent. However, this duty of confidentiality is not unlimited.

Irrespective of consent, disclosure may be necessary in the public interest when failure to disclose may expose the patient or others to risk of serious harm. In such circumstances, the doctor must disclose the information promptly to an appropriate person or authority. Disclosure is also justified for the detection and prevention of serious crime, to satisfy a statutory requirement, or following an order of the court.

General Medical Council (GMC) guidance entitled 'Confidentiality: Guidance from the General Medical Council' (1995) confirms that disclosure may be made to satisfy a statutory requirement, for example, those related to controlled drugs or communicable diseases (Principle 20 of GMC guidance) or on the direction of a court. The guidance also states that only so much of the patient's (or deceased person's) notes and records as is relevant should be disclosed (Principle 20).

Producing the report

To produce the report it should, in Scotland, be accompanied by a witness statement (LPS 9) providing necessary personal details for a witness summons to be issued by the fiscal. The usual form of words in the witness statement is as follows:

"I produce a report of my findings [X pages long] as exhibit XX/1 [initials of the author and the report followed by a number: this will always be '1' unless the expert has already produced exhibits in their LP 70 statement], which is signed by me and dated [date of signature]".

When a witness (including an expert) signs a statement on form LP 70 / LPS 9, s/he signs a declaration that states that the content of the statement is true to the best of his/her knowledge. The witness also accepts that s/he might be prosecuted if s/he knowingly states something which s/he knows to be untrue. The responsibility for the final content of the report remains with the author.


The expert should produce any presentational material that s/he has produced, and s/he may refer to productions produced by others, such as photographs, sketches, models, plans, tables and graphs. Even in the simplest of cases, illustrative material may be very helpful in explaining the case to the court.

Extrinsic material

The expert should bring to the attention of the prosecutor and the court any material that will help decide the case. This may include articles, published papers, codes of practice, guidance, published and unpublished research reports etc. References to material to which the defendant would or should have had access may be particularly useful.

Courts have taken account of official publications in a number of reported cases and an employer is under a duty to keep abreast of developing knowledge. Some material may be illustrative and some may set standards either for analysis or safety.

The expert should produce with the report any material to which s/he refers, or the relevant extract from it, and s/he should have the whole document or publication available in court.

Some documents may be produced without being produced with the report (for example, approved codes of practice) but the expert should nevertheless produce the document and explain its significance. Regulations may also require explanation.

The expert may need to do a literature search or obtain a statistical analysis, and if s/he can verify that analysis, it will not be necessary to call the statistician. S/he may use material stored in a computer; for guidance on the admissibility of such evidence, see the sections Preparing evidence for court and Computer evidence.

The defence may object to reference to other documents (of which the expert is not the author) on the grounds of hearsay. Examples of such documents include British/EN standards, HSE guidance notes, industry publications, calculation tables, textbooks, articles and summaries of research. The prosecutor must establish that the expert is competent to express an opinion on such material; where it does form part of the expert's body of expertise, the expert may refer to the material in order to support his/her opinion without infringing the rules against hearsay.

Updating the report

As indicated in 'Contents of the report' above, after an expert report has been produced, matters may arise that require the report to be amended. Consideration should be given as to whether a new, revised report is necessary or whether, if the changes are only minor, additional information could be produced in the form of a supplementary report. Details of the changes, referring to the sources of any new or additional information and setting out any revised conclusions, must be recorded.

Any such amendments or new material must be communicated to the lead investigating inspector forthwith for onward transmission to the procurator fiscal who will then have duty to disclose to the defence prior to trial.

Draft reports

The report of an expert should not be signed at an early stage; it should initially be considered a draft and marked as such. This is because:

  • the expert will not necessarily have seen all the evidence;
  • the expert may consider on reflection that the case, or a part of it, is outside his/her expertise; and
  • the informations/complaint/charges and the ambit of the investigation may not yet have been finalised.

Draft reports and statements should be retained, as they may be disclosable to the defence (see below). Whether draft reports will in fact be disclosed at a later stage will be a matter for the prosecutor, who will apply the appropriate legal tests.


In Scotland the process of disclosure is entirely managed by the procurator fiscal. However, HSE has a duty to disclose to the fiscal all relevant evidence and information particularly if it may undermine the prosecution case.

Laboratory reports

As with any other expert report, these should be in the form of a report supported by a signed statement, The statement should be given on form LPS 9 and typed (double-spaced). Laboratory reports can often be agreed.

The expert should refer to the section 'Contents of the report' above and ensure that his/her involvement in the tests is clearly stated. For example, s/he should either say: "The tests were carried out by me" or "The tests were carried out in my presence and under my direct personal supervision".

Standards, conduct and consultation

The specialist will need to:

  • agree with the investigating inspector the nature of the science, technology or medical support required;
  • maintain a communication record; and
  • retain all information relating to the incident and make it available to the investigating officer/disclosure officer on request.

Consultation with colleagues, including the line manager, can provide the specialist/expert with an opportunity to:

  • develop and explore opinions on the issues involved;
  • identify other areas for consideration;
  • examine the foundation of any assertions reported;
  • ensure appropriate team working; and
  • info rm future action.

Professional oversight of a specialist's work by his/her line manager is useful in establishing a benchmark for quality and accuracy and can be done without compromising personal authorship of the report.

Discussion of the content of a report between the specialist and the inspector or procurator fiscal is entirely proper, provided care is taken to ensure that the report is, and is seen to be, the expert's own product. When an inspector, or anyone else, communicates with an expert, whether in-house or from outside, they should be careful to ensure that there is no risk that the communication could be misinterpreted so as to suggest that it might influence the expert's opinion.

Both the specialist/expert and the inspector (or other person) instructing him/her should remember that all communications (including draft reports), other than those between an expert and lawyers, may be liable to be disclosed. Communications between the expert and the procurator fiscal in the case are privileged.

The expert should set out in his/her report only those facts that have been, or are to be, proved in evidence and other expert opinion upon which s/he bases his/her opinion. S/he can refer to written admissions made by the defendant. Experts should be aware that, just as a party must challenge in cross-examination contested evidence given by a witness of fact, so the opinions of an expert must be challenged if they are disputed.

Before any decision to approve a Prosecution Report is taken, it is permissible for an expert to advise as to whether, in his/her opinion, there is any breach of the law; the balance of legal opinion permits an expert to give opinion on what has been called "the ultimate issue". However, experts should be careful; where an expert deals with such an issue in his/her report, the sheriff or judge in a trial must direct the jury that they are not bound by the expert's opinion, and that the issue is for them to decide.

Following a plea of not guilty in a case to trial the defence must serve its expert evidence on the prosecution as soon as practicable. The procurator fiscal should ensure that the prosecution expert sees this evidence and provide comments. They may be asked him/her to prepare a further report dealing with the defence evidence.

An expert should consider the lines of argument that the defence may put forward. In a covering minute (rather than the report), the expert should deal with:

  • any defences which are possible but unlikely;
  • matters which the expert may deal with in a certain way if they arise; and
  • any suggestions for further expert evidence.

An expert may also prepare notes for the procurator fiscal to use when cross-examining.

The courts have determined that witnesses should not be deterred from giving evidence by the fear of litigation; it is not in the public interest for expert witnesses to be sued for the evidence they give in court. That immunity applies as much to an expert as to any other witness. However, an expert is not immune from action if s/he produces a report, or provides information with a view to it being used in court, that is so flawed that it might amount to serious professional misconduct.

The courts have also concluded that the same public policy should protect experts from the risk of a complaint to the relevant professional body arising from anything said by that expert whilst giving evidence. However, experts owe an overriding duty to the court; the judge hearing the expert evidence can still refer the expert's conduct to the relevant professional body if satisfied that the conduct has fallen far below what is expected so as to merit disciplinary action. The judge must be of the opinion that the expert needs to be removed from practice, or at least subjected to disciplinary action that might prevent that person from acting as an expert witness.

The above exemptions relate to evidence given in court. In the preparation of their evidence, and in their conduct before and during the proceedings whilst outside the witness box, witnesses instructed by or on behalf of HSE are expected to act professionally and in line with their contract of employment or instructions. Expert witnesses may be the subject of management control and/or auditing to ensure quality and accuracy. Experts can legitimately be asked to account for any delay caused in providing their written opinions and may be required to do so in open court.

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Updated 2022-03-31