Understanding Burden of Proof

Introduction

The burden of proof is the rule that decides who must prove what, and to what level, in a case. It shapes how disputes are resolved in both civil and criminal courts. In short: the party making an allegation must back it with evidence that meets the correct standard. If they cannot, they lose on that point.

Two ideas sit under the banner of “burden of proof”:

• The legal (or persuasive) burden: who must persuade the court of a fact.
• The evidential burden: who must point to enough evidence to raise an issue.

Standards differ by context. Civil cases work on the balance of probabilities (more likely than not). Criminal prosecutions require proof beyond reasonable doubt (jurors are told they must be sure). Some defences put an evidential burden on the defendant; a few impose a legal burden by statute (for example, insanity in crime or certain statutory defences).

There are also recognised exceptions and special rules, such as “material increase in risk” in industrial disease claims, and different tests for self-defence in tort compared with crime. Understanding who carries which burden, and the standard to be met, is central to case strategy.

What You'll Learn

• What legal and evidential burdens mean, and how they differ
• The standards of proof in civil and criminal proceedings
• When and how burdens can shift between parties
• Reverse burdens created by statute and how courts approach them
• Key cases: McGhee, Fairchild, Nimmo, Bratty, Ashley, Lambert, Sheldrake, Barton v Armstrong, Museprime, Hill v Baxter
• Practical steps to plead, prove, and defend claims using the correct burden and standard

Core Concepts

Legal vs Evidential Burden

• Legal (persuasive) burden

  • The duty to persuade the court that a fact is true.
  • In civil cases, the claimant usually bears the legal burden on each element of the cause of action; defendants carry it on any positive defence (e.g., contributory negligence).
  • In criminal cases, the prosecution bears the legal burden on actus reus and mens rea beyond reasonable doubt. The defendant carries the legal burden only for a few defences (e.g., insanity, diminished responsibility), usually on the balance of probabilities.

• Evidential burden

  • The duty to point to enough evidence to make an issue “live” in the case.
  • Once the evidential burden is met on a defence such as self-defence, automatism, or duress, the legal burden typically falls on the prosecution to disprove it to the criminal standard.
  • In civil claims, evidential burdens can move as the case unfolds; for example, after the claimant shows a misrepresentation likely to induce a reasonable person, the representor may need to show the claimant was not actually induced.

Key point: the legal burden tends to stay where the law places it; the evidential burden can move back and forth as evidence is produced.

Standards of Proof: Civil vs Criminal

• Civil: balance of probabilities

  • The court decides if a fact is more likely than not.
  • The standard is constant, but more serious allegations (e.g., fraud) may call for clearer evidence before the court feels able to find them proven on that standard.

• Criminal: beyond reasonable doubt

  • Jurors are directed they must be sure of guilt.
  • This does not mean absolute certainty. If there is a reasonable doubt, the defendant must be acquitted.
  • Where the defendant bears a legal burden (e.g., insanity), the standard is the balance of probabilities unless statute says otherwise.

Shifting Burdens and Reverse Burdens

• Shifting evidential burdens

  • Example: self-defence. The defendant need only raise evidence to put the issue in play; the prosecution must then disprove self-defence beyond reasonable doubt.
  • Example: automatism. The defendant must produce some evidence of an involuntary act; the prosecution must then prove the act was voluntary or that a different legal category (e.g., insanity) applies.

• Reverse legal burdens

  • Some statutes require the defendant to prove a defence (often phrased “to prove” or “to show”).
  • Courts assess compatibility with the right to a fair trial. Where possible, they interpret reverse burdens as evidential rather than legal.
  • Key authorities: R v Lambert (reading a reverse burden down to an evidential burden) and Sheldrake v DPP (proportionality analysis where Parliament has clearly imposed a legal burden).

Presumptions and “Precedent Facts”

• Presumptions can affect burdens (e.g., statutory presumptions about possession or age).
• In public law and some tribunals, the court may determine a “precedent fact” for itself (e.g., whether a person is a child), without treating the issue as one party’s legal burden. R (CJ) v Cardiff City Council is a leading illustration.

Key Examples or Case Studies

• Robinson v Harman (1848)

  • Context: damages for breach of contract.
  • Takeaway: the claimant must prove a valid contract, breach, and loss on the balance of probabilities to recover expectation damages.

• Barton v Armstrong [1976] AC 104

  • Context: contractual duress.
  • Takeaway: the threatened party need only show the threats were a reason for contracting. The onus then shifts to the other party to show the threats made no difference.

• Museprime Properties Ltd v Adhill Properties Ltd (1990)

  • Context: misrepresentation and inducement.
  • Takeaway: if a statement would have induced a reasonable person, the representor may have to show the claimant was not actually induced.

• R v Steane [1947] KB 997

  • Context: proving intention in crime.
  • Takeaway: the prosecution must prove intent beyond reasonable doubt; where evidence points to acting under pressure or for a different purpose, intent cannot simply be assumed.

• Bratty v Attorney General for Northern Ireland [1963] AC 386

  • Context: automatism and insanity.
  • Takeaway: the defendant must raise evidence of automatism; the prosecution must then negate it. Where the condition is “disease of the mind,” the insanity rules apply and the defendant bears the legal burden on that defence.

• Hill v Baxter [1958] 1 QB 277

  • Context: involuntary acts in driving cases.
  • Takeaway: examples such as being overcome by a swarm of bees show that a truly involuntary act can negate the actus reus; the defendant must adduce some evidence before the issue goes to the tribunal of fact.

• Nimmo v Alexander Cowan & Sons Ltd [1968] AC 107

  • Context: breach of statutory duty in workplace safety.
  • Takeaway: once the claimant shows the workplace was unsafe, the employer must prove that it was not reasonably practicable to do more.

• McGhee v National Coal Board [1973] 1 WLR 1 and Fairchild v Glenhaven Funeral Services Ltd [2002] UKHL 22

  • Context: causation and material increase in risk.
  • Takeaway: where scientific uncertainty makes exact causation impossible to prove and the claimant was exposed by several employers, proof of a material increase in risk can be enough. In mesothelioma cases, this principle is supported by statute (Compensation Act 2006, s.3).

• Ashley v Chief Constable of Sussex Police [2008] UKHL 25

  • Context: self-defence in tort vs crime.
  • Takeaway: in tort, the defendant must show both an honest and reasonable belief in the need to use force; in crime, an honest belief can suffice (reasonableness is still relevant evidence).

• R v Lambert [2002] 2 AC 545 and Sheldrake v DPP [2004] UKHL 43

  • Context: reverse burdens and fairness.
  • Takeaway: courts may interpret reverse burdens as evidential to protect fair trial rights; where a true legal reverse burden remains, it must be justified and limited.

Practical Applications

• Map the elements

  • List each element of your claim or charge and any defences. Allocate who carries the legal burden for each.
  • Note any statutory reverse burdens or presumptions.

• Plan to the standard

  • Civil: ask whether your evidence makes the point more likely than not. Use contemporaneous documents and clear witness statements.
  • Criminal: for the prosecution, test whether each element is proved so the tribunal is sure; for the defence, look for reasonable doubt and prepare to raise any defence with enough evidence.

• Manage evidential burdens

  • If relying on a defence (self-defence, duress, automatism), prepare evidence sufficient to put the issue in play. Once raised, press the other side’s duty to disprove it (in crime) or meet it (in civil).

• Use case-specific rules

  • Industrial disease: consider material increase in risk where direct proof of causation is not possible.
  • Workplace safety: after showing an unsafe state, press the employer’s duty to show what was reasonably practicable.

• Get the directions right

  • In jury trials, ensure directions on the burden and standard are accurate (e.g., “sure” for criminal standard). Seek clarification if there is any risk of confusion.

• Deploy procedural tools

  • Criminal: consider a “no case to answer” submission if the prosecution has not met its legal burden on one or more elements.
  • Civil: summary judgment or strike out may be appropriate if the other side has no real prospect of meeting their burden.

• Watch fairness and human rights points

  • If a statute appears to impose a legal burden on the defendant, consider whether it can properly be read as an evidential burden (Lambert) or whether the burden is compatible with fair trial rights (Sheldrake).

• Keep records of causation and inducement

  • For misrepresentation and duress, gather evidence on decision-making: who said what, when, and how it affected the choice to contract.

Summary Checklist

• Identify the legal and evidential burdens for every live issue.
• Apply the correct standard: balance of probabilities (civil) or beyond reasonable doubt/“sure” (criminal).
• Raise defences with enough evidence to shift the evidential burden where applicable.
• Check for reverse burdens in statute; consider Lambert/Sheldrake principles.
• In industrial disease, assess whether “material increase in risk” applies (Fairchild; Compensation Act 2006, s.3).
• For workplace safety claims, be ready to require the employer to show what was reasonably practicable (Nimmo).
• For self-defence, remember the civil test (honest and reasonable) vs criminal (honest, with reasonableness as evidence).
• Ensure accurate directions on burden and standard; use procedural routes if the other side has not met their burden.

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