Proving the offence

What is evidence?

1. Evidence is information that may be presented to persuade the court of the probability of the truth of some fact asserted in the case, ie information by which facts tend to be proved or disproved.

Fact-finding in the trial

2. Facts at issue in criminal cases are those that the prosecution must prove if it is to succeed, together with any facts that the defendant may wish to raise in his/her defence. The prosecution must prove all the elements of the offence. Examples of facts that may need to be proved are:

  • the identity of the defendant;
  • that the defendant is an employer;
  • that an employee was 'at work' at the time s/he was injured.

3. The elements of an offence will appear as items on the evidence matrix that is submitted to the Approval Officer as part of the prosecution report.

4. A trial is a fact-finding exercise and, with its verdict, the court makes a decision as to whether all elements of the offence have been proved. Fact-finding might appear to be straightforward: the two parties put before the court their evidence to support a particular version of the facts in dispute, and the court decides which version it prefers. However, there are rules that govern how this process is to be conducted – rules of evidence, such as the hearsay rule, and rules of procedure. These rules are necessary to ensure that a defendant receives a fair trial and is not unfairly convicted.

The burden of proof

5. The burden of proving the guilt of the defendant lies on the prosecution, who must prove the particulars of the offence beyond reasonable doubt; the jury or magistrates should only convict if they are sure of the defendant's guilt.

6. A key question for consideration is which party has the obligation ('the burden') to prove particular facts in issue. A court will look primarily at the wording of the statutory provision when making this decision.

7. The words 'shall' or 'shall not', used in statutory provisions, impose an absolute obligation to do, or not to do, the act in question. It is not possible for a defendant to argue that it is impracticable, difficult or even impossible to do it, or not to do it. For example, section 7 HSWA states: "It shall be the duty of every employee while at work–

  1. to take reasonable care for the health and safety of himself and of other persons who may be affected by his acts or omissions at work; and
  2. as regards any duty or requirement imposed on his employer or any other person by or under any of the relevant statutory provisions, to co-operate with him so far as is necessary to enable that duty or requirement to be performed or complied with."

8. By the use of the word "shall", this section imposes absolute duties on the employee. Once the prosecution has proved that an employee did not take reasonable care as required, the offence1 is proved, whether or not the defendant realised that what s/he was doing fell below an acceptable standard of conduct.

Reasonable practicability

9. The duty set out at section 7(a) HSWA is to take 'reasonable care'. There is a distinction between the duty to take reasonable care and the duty to ensure health and safety 'so far as is reasonably practicable'.

10. Under the HSWA and certain regulations, a duty holder may be required to do something 'so far as is practicable' or 'so far as is reasonably practicable'. In these situations, section 40 HSWA applies (see 'Reverse burdens' below).

11. 'Reasonably practicable' is a lesser standard than 'practicable'. The duty holder must balance the risk against the sacrifice (whether in money, time or trouble) involved in taking the measures needed to avert the risk. If there is a gross disproportion between them, the risk being insignificant relative to the sacrifice, the defendant is not required to take any further measures and so discharges the duty2. In assessing what is 'reasonably practicable' in relation to the general duties under sections 2, 3 and 4 HSWA, the likelihood of a risk eventuating (which includes some consideration of what is reasonably foreseeable) is relevant.3

12. Where the obligation is qualified by the word 'practicable', the standard is stricter: the duty holder should do what is necessary to reduce the risk regardless of the cost (in time or money). The measures must be possible in the light of current knowledge and invention.

13. It will be for the court to decide as a question of fact (based on the evidence presented) whether or not something was practicable or reasonably practicable.

14. The requirement under sections 2,3 and 4 HSWA to ensure something 'so far as is reasonably practicable' operates to qualify the duty rather than acting as a defence.4

15. There are two principal burdens (or 'obligations to prove') in legal proceedings: the legal burden and the evidential burden.

16. The legal burden5 is the obligation on a party to prove a fact in issue. In criminal proceedings, the prosecution normally has the legal burden of proving, beyond reasonable doubt, all elements of the offence. Whether this burden has been discharged is decided by the magistrates or jury at the end of the trial, when all the evidence has been presented. If the prosecution has not discharged this burden, the case will fail.

17. The evidential burden is the obligation to adduce sufficient evidence on a fact in issue to justify, as a possibility, a favourable finding on that issue by the magistrates or jury. Whether the evidential burden has been discharged is decided, during the course of the trial, by the judge (for example, following a defence submission of 'no case to answer'). The prosecution must adduce sufficient evidence to prevent the judge withdrawing that issue from the jury. Even where the evidential burden is discharged on a particular issue, the evidence may not be sufficient to discharge the legal burden on that issue.

18. A party bearing the legal burden on a particular issue usually also bears the evidential burden of proving that issue. Two exceptions are:

  • certain criminal defences6; and
  • 'presumptions'.

19. In certain criminal defences, the burden on the defence may be 'evidential only': the defence merely has to raise sufficient evidence for the matter to be considered by the court. The burden then passes to the prosecution to prove the matter beyond reasonable doubt. However, this is not the case with the reverse burden under section 40 HSWA (see below)7; this exception does not therefore apply to health and safety offences.

20. A presumption is where a court treats a fact as having been proved, notwithstanding that no (or insufficient) evidence has been presented to establish it. A presumption can help the prosecution to prove a particular fact by requiring the defence to disprove it. For example, it will be presumed as a matter of law that:

  • a properly addressed and posted letter, not returned, has reached its destination; and
  • a person acting in an office was properly appointed.

21. These facts will be 'presumed' by the court unless the defence presents sufficient evidence to the contrary to rebut the presumption.

Reverse burdens

22. When the burden of proof is on the defendant to establish a particular issue, it is often referred to as a 'reverse burden', because it reverses the normal situation in which the prosecution must prove the facts beyond reasonable doubt.

23. Section 40 HSWA imposes such a reverse burden: where a duty holder is required to do something 'so far as is practicable' or 'so far as is reasonably practicable', the burden is on the defendant to prove that it was not practicable or reasonably practicable to do more than was in fact done. The Court of Appeal has ruled that the burden of proof imposed on the defendant by section 40 is a legal burden (see above), which is justified, necessary and proportionate.8

24. Similarly, under section 17 HSWA, if an accused is proved not to have followed a relevant provision in an Approved Code of Practice, the failure to do so will be taken by the court as proof of contravention of the legal requirement in question unless the accused can show that s/he satisfied the requirement by adopting suitable alternative measures.

25. Where a legal burden of proof is on a defendant, s/he can satisfy it if s/he proves the issue on the balance of probabilities9. This is the same standard as that placed on a claimant in a civil action; s/he need not prove the issue beyond reasonable doubt.

Advance rebuttal

26. Despite the reverse burden under section 40 HSWA, it is nevertheless advisable in cases involving reasonable practicability to adduce evidence during the prosecution case to show what measures it would have been reasonably practicable for the defendant to take. The opportunity to do this may be lost once the prosecution case has closed.

27. This is known as 'advance rebuttal' and has been recognised by the courts10. It may involve, for example, adducing expert evidence or HSE or industry guidance to counter any potential defence arguments as to foreseeability (see 'Reasonable practicability' above), including evidence of wider custom and practice, human factors or the hierarchy of control measures11 in cases where the defence may argue that the actions (or omissions) of an employee were not foreseeable.

28. In addition, one of the factors the court may take into account in determining sentence is how far short of the appropriate standard the defendant fell in failing to meet the reasonably practicable test. 12


  1. Different offences will apply depending on the circumstances of the case. Back to reference of footnote 1
  2. Edwards v National Coal Board [1949] 1 KB 704, CA; Austin Rover Group Ltd v HM Inspector of Factories [1990] 1 AC 619, HL. Back to reference of footnote 2
  3. R v HTM Ltd [2006] EWCA Crim 1156. Back to reference of footnote 3
  4. R v HTM Ltd [2006] EWCA Crim 1156. Accordingly, the Court of Appeal held that regulation 21 of the Management of Health and Safety at Work Regulations 1999, which states that an employer may not rely on an act or default of an employee as a defence in proceedings under any of the relevant statutory provisions, does not apply to the general duties under sections 2 and 3 HSWA. Back to reference of footnote 4
  5. Sometimes referred to as the 'persuasive', 'probative' or 'ultimate' burden. Back to reference of footnote 5
  6. These defences, for example self-defence, will not normally have application in health and safety cases. Back to reference of footnote 6
  7. R v Davies [2002] EWCA Crim 2949. Back to reference of footnote 7
  8. R v Davies [2002] EWCA Crim 2949. By contrast, see R v Keogh [2007] EWCA Crim 528: a reverse burden of proof under sections 2 and 3 of the Official Secrets Act 1989 should be treated as an evidential burden only, in order to ensure compatibility with Article 6 of the European Convention on Human Rights (the right to a fair trial). Back to reference of footnote 8
  9. See, for example, R v Lambert [2001] UKHL 37: "If [a legal burden of proof on an accused] is created the matter in question must be taken as proved against the accused unless he satisfies the jury on a balance of probabilities to the contrary … If [an evidential burden only on the accused] is adopted the matter must be taken as proved against the accused unless there is sufficient evidence to raise an issue on the matter but, if there is sufficient evidence, then the prosecution have the burden of satisfying the jury as to the matter beyond reasonable doubt in the ordinary way … A transfer of a legal burden amounts to a far more drastic interference with the presumption of innocence than the creation of an evidential burden on the accused" (Lord Steyn, para 37). Back to reference of footnote 9
  10. R v Associated Octel Co. Ltd [1996] 1 WLR 1543. Back to reference of footnote 10
  11. The principles of prevention are set out in the Management of Health and Safety at Work Regulations 1999, regulation 4 and schedule 1. Back to reference of footnote 11
  12. R v Howe & Son (Engineers) Limited [1999] 2 All ER 249. Back to reference of footnote

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Updated 2021-08-27