Illegally or Improperly Obtained Evidence: does it matter how you get it?

Written by Meg Gibson

“It matters not how you get it; if you steal it even, it would be admissible in evidence.

This statement was made by Crompton J in Leathem (1861)1, and it is often cited as authority for the general rule that all relevant evidence is admissible in English criminal proceedings. To some, this might seem strange. In private law, a claimant’s own illegal act may very well prevent him from recovering damages from another.Thus, it seems strange that evidence that is illegally or improperly obtained is admissible. In this article, I will first consider whether this statement is an accurate reflection of contemporary English law’s approach to illegally obtained evidence. Then, I will explore the justifications for this approach are and if a different approach should be adopted.

An accurate reflection of English law’s approach?

Traditionally, Crompton J’s dictum reflected the approach of English law. A breach of rules in the criminal proceedings against a person under investigation is treated as irrelevant to the question of whether the evidence will be admissible. Automatic exclusion of evidence illegally or improperly obtained has never been adopted by the English courts.

However, there has been a shift in the Courts towards adopting the solution that evidence obtained illegally or improperly may be excluded sometimes. This suggests that it can in fact sometimes matter how you get the evidence. In Sang,2 it was asserted that the judge exercises powers in relation to whether admitting the evidence would make the trial unfair; it is not a discretion as to whether the fact the evidence was illegally obtained should make it inadmissible. The test in Sang weighed prejudicial effect against probative value. This means that section 78 of the Police and Criminal Evidence Act (PACE) 1984 can exclude evidence if the judge “is of the opinion that its prejudicial effect on the jury was likely to outweigh its probative value” [Lord Diplock at 14].

78 –  Exclusion of unfair evidence.

(1) In any proceedings, the court may refuse to allow evidence on which the prosecution proposes to rely to be given if it appears to the court that, having regard to all the circumstances, including the circumstances in which the evidence was obtained, the admission of the evidence would have such an adverse effect on the fairness of the proceedings that the court ought not to admit it.

(2) Nothing in this section shall prejudice any rule of law requiring a court to exclude evidence.

For example, in the case of Delaney,3 the fact that the evidence was unreliable and the police breached rules by failing to keep a record of the evidence meant that it was not admissible in court. This offers a contradiction to Crompton J’s statement; it can matter how you get the evidence if admitting it would render the proceedings unfair. It is therefore a matter of judgement on the part of the judge to determine whether the evidence would in fact be admissible, taking this into account.

Moreover, in A and Others v Secretary of State for the Home Department,4 if on a balance of probabilities it seems as if evidence was obtained in violation of Article 3 of the ECHR (i.e., by torture), then it should be excluded. If oppression was used or anything said or done rendered unreliable a confession given, then the evidence is automatically excluded. Based on this, it would seem that Crompton J’s assertion is fundamentally flawed in relation to contemporary English law. Whilst there is a discretion to admit illegally obtained evidence, this does not mean that it never matters how you get it.

However, PACE section 76(2) only applies to confessions, not to other forms of evidence:

76 – Confessions.

(2) If, in any proceedings where the prosecution proposes to give in evidence a confession made by an accused person, it is represented to the court that the confession was or may have been obtained—

(a) by oppression of the person who made it; or

(b) in consequence of anything said or done which was likely, in the circumstances existing at the time, to render unreliable any confession which might be made by him in consequence thereof,

the court shall not allow the confession to be given in evidence against him except in so far as the prosecution proves to the court beyond reasonable doubt that the confession (notwithstanding that it may be true) was not obtained as aforesaid.

It may therefore be more accurate to say that in contemporary English law, it does not matter how you get other forms of evidence, provided that such evidence will not have an adverse effect on the fairness of proceedings. As was asserted by Lord Hoffman in A, the general rule remains: any relevant evidence is admissible.

Justifications for such an approach:

But should this be how contemporary English law approaches evidence obtained improperly or illegally?

The approach of section 78 in allowing for discretion can arguably be seen as sufficient, particularly if viewed in terms of a triangulation of interests: balancing the interests of the complainant, the defendant and society as a whole. In Attorney General’s Reference (No 3 of 1999),5 a rapist whose DNA as wrongly detained by police from an earlier burglary was caught using this DNA. The House of Lords held that although the police should not have kept the DNA, it would be strange to say that the defendant could not be prosecuted despite having the evidence available against them.

This suggests that to change the rule in Section 78 to one where illegally obtained evidence is always inadmissible could lead to this ‘triangulation of interests’ becoming imbalanced, with less consideration being given to the interests of the complainant and society. To release a person that is strongly suspected of being a rapist back into society on the basis that a technical or procedural mistake meant that they were caught for a crime they committed would seem at odds with this balancing act. It would negate the fact that there is the interest of the victim in having their attacker punished and the paternalistic interests of society in a rapist being imprisoned. Therefore, it seems that cases where there are minor technical details that mean evidence is illegally obtained (such as forgetting to delete DNA off of the system) does not necessarily make the trial so unfair to the defendant that essential evidence should be barred. In this respect, section 78 of PACE does help to balance these interests.

However, Section 78 and the balancing act it provides is vague. It could benefit from having a more transparent approach, particularly in relation to when evidence would have an adverse effect on the fairness of the proceedings. The fact that the House of Lords appeared to accept in A that in some circumstances, how evidence is obtained can unequivocally make it inadmissible, notwithstanding its reality and source, is at odds with the conventional approach of English law. It may therefore be worthwhile to have a clearer approach to when evidence is inadmissible due to Convention rights such as Article 3 being breached. Since it is accepted that a breach of Article 3 leads to automatic exclusion, the law not incorporate breaches of other Convention rights to automatically exclude evidence obtained from these breaches?

Choo and Nash argue that although Article 8 is of a different tenor from Article 3, it is subject to qualifications and limitations. They suggest that determining a violation of Article 8 and other Convention has occurred is therefore still a serious breach of the defendant’s rights and means that the evidence obtained should be excluded.6

If this view is taken, then surely a breach of any of the Convention rights would infringe upon the right to a fair trial, enshrined in Article 6? Dissenting with the majority in Khan, Judge Loucaides remarked:

“I cannot accept that a trial can be fair, as required by Article 6, if a person’s guilt for any offence is established through evidence obtained in breach of the human rights guaranteed by the Convention”.7

Breaching Convention rights that are supposed to guarantee fundamental freedoms and protect individual rights seems contrary to the interests of not only the defendant, but society too – relating back to this idea of the triangulation of interests. Suggesting that the prosecution should be able to use evidence in the trial that breaches the rights set out in the Convention would undermine the purpose of having these rights there in the first place. Otherwise, allowing the breach of these international standards by making such evidence admissible would “compromise the integrity of the judicial process” and “dishonour the administration of justice” according to Lord Hoffman.

However, if we take Article 8 of the ECHR, we may wonder whether automatic exclusion of evidence would underplay the interests of society and the complainant in having a factually guilty person convicted. This relates back to the aforementioned Attorney-General case. Although the defendant’s right to his private life may have been breached by the police improperly keeping his DNA, it seems absurd to then let him escape conviction because of this. Perhaps, then, some qualification of how “seriously” the defendant’s Convention rights have been breached must be adopted to determine whether the evidence should be automatically excluded.


It can matter in English law how evidence is obtained. Although the general rule is that any relevant evidence is admissible regardless of how it was obtained, section 76 of PACE highlights how the way confessions are gained can affect the admissibility of the evidence. Furthermore, although section 78 provides discretionary powers relating to evidence being inadmissible if it would be averse to fairness, the House of Lords have accepted in A that some illegally obtained evidence cannot be used if it breaches Article 3.

Yet, more could be done to improve the transparency of English law’s approach to this matter. It would be in the interest of the individual and society to uphold the rights set out in the ECHR by qualifying when breaches of these would lead to an automatic exclusion of evidence. Otherwise, English law may be vulnerable to incoherence and fail to respect the necessity of trial fairness within the criminal justice system, by affording the prosecution an unfair advantage.


  1. R v Leathem (1861) 8 Cox CC 498
  2. R v Sang [1980] AC 402 [1979] Crim.L.R. 655
  3. Delaney (1989) 88 Cr App R 338
  4. A and Others v Secretary of State for the Home Department [2005] UKHL 71, [2006] 2 AC 221, referred to as A henceforth
  5. AG’s Ref (No 3 of 1999) [2001] 2 WLR 56, [2001] AC 91
  6. A.L.Choo and S.Nash, “Improperly Obtained Evidence in the Commonwealth: Lessons for England and Wales?” (2007) 11 E&P, p.88
  7. R v Khan [1995] QB 27