Principles and procedures to admit and exclude evidence - Co...

Learning Outcomes

This article outlines the legal framework governing the exclusion of bad character evidence in criminal trials in England and Wales, focusing on the court’s powers under section 78 of the Police and Criminal Evidence Act 1984 (PACE 1984) and section 101(3) of the Criminal Justice Act 2003 (CJA 2003). It covers the distinction between discretionary and mandatory exclusion, the operation of the bad character gateways, how admissibility is weighed for previous convictions and non-conviction misconduct, the factors guiding fairness (including the manner in which evidence is obtained, probative value versus prejudicial effect, elapsed time, and risks of unfair prejudice or confusion), the procedural framework for exclusion applications (notice, written and oral submissions, and timing in the Magistrates’ Court and Crown Court), and the overarching role of Article 6 ECHR and the courts’ general powers to regulate evidence, with practical links to criminal litigation scenarios, statutory interpretation, and evolving case law.

SQE1 Syllabus

For SQE1, you are required to understand the court’s powers to regulate the admission and exclusion of bad character evidence in criminal trials, with a focus on the following syllabus points:

• the role of the court in regulating the admission and exclusion of evidence to ensure the fairness of proceedings
• the statutory bases for exclusion of evidence: s.78 PACE 1984 (discretionary power) and s.101(3) CJA 2003 (mandatory exclusion of bad character)
• the seven gateways for the admissibility of bad character evidence under s.101(1) CJA 2003
• application of the principles of probative value and prejudicial effect in criminal evidence
• procedural requirements for notice and objection in the Criminal Procedure Rules
• defendants’ rights under Article 6 ECHR with respect to the right to a fair trial

Test Your Knowledge

Attempt these questions before reading this article. If you find some difficult or cannot remember the answers, remember to look more closely at that area during your revision.

1. Under which section of PACE 1984 does the court have a general discretion to exclude unfairly obtained prosecution evidence?
   1. s 76
   2. s 78
   3. s 101
   4. s 114
2. Which gateways for admitting bad character evidence under the CJA 2003 are subject to a specific mandatory exclusion test under s 101(3) CJA 2003?
   1. Gateways (a) and (b)
   2. Gateways (c) and (f)
   3. Gateways (d) and (g)
   4. All gateways

3. True or false? A court must exclude bad character evidence admitted under gateway (d) (propensity) or (g) (attack on another's character) if its admission would have such an adverse effect on the fairness of the proceedings that it ought not to be admitted.

4. Does the court's discretion under s 78 PACE 1984 apply only to confession evidence?

Introduction

The exclusion of evidence in criminal proceedings is a fundamental judicial control to protect the right to a fair trial, particularly regarding the admission of a defendant's bad character. The Criminal Justice Act 2003 (CJA 2003) provides a framework of seven gateways through which bad character evidence may be admitted, but this scheme is supported by essential exclusionary powers. The court must ensure that the presentation of such evidence does not unfairly prejudice the tribunal of fact or undermine the fairness of the proceedings. Powers to exclude are found both in section 78 of the Police and Criminal Evidence Act 1984 (PACE 1984), granting a broad judicial discretion, and in section 101(3) of the CJA 2003, which imposes a mandatory exclusion in certain defined situations. Understanding how, why, and when courts may (or must) exclude bad character evidence is a fundamental aspect of fair trial rights and an important area for those preparing for SQE1 and legal practice.

Key Term: Bad Character Evidence
Evidence of, or a disposition towards, misconduct including previous convictions, allegations, or conduct considered reprehensible, but excluding evidence directly related to the facts of the offence charged or the investigation/prosecution of that offence.

Key Term: Mandatory Exclusion
A court's legal obligation, rather than mere discretion, to refuse admission of evidence where statutory conditions are met, as under s.101(3) CJA 2003 for certain bad character gateways.

Exclusion under s 78 PACE 1984

Section 78 of PACE 1984 provides a broad and flexible power allowing a court, in any criminal proceedings, to refuse to admit evidence on which the prosecution proposes to rely if its admission would have such an adverse effect on the fairness of the proceedings that the court ought not to admit it. This discretion is available not only in relation to confession evidence, but to all types of prosecution evidence, including forms of bad character evidence not subject to mandatory exclusion.

Key Term: Section 78 PACE 1984
Section 78 gives the court a general discretion to refuse evidence offered by the prosecution if, “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.”

The application of s 78 is not confined to situations of unlawful or improper police conduct, although violation of PACE or the Codes of Practice (such as in searches, arrest, or interview) is a common basis for such applications. The focus is always on the potential impact on a fair trial. The remedy is discretionary; the court may exclude or admit the evidence as it thinks fit.

Factors Considered under s 78

The factors the court considers when deciding whether to exclude evidence under s 78 PACE 1984 are broad and case-specific. They include:

• How the evidence was obtained: Significant and substantial breaches of PACE or the Codes of Practice, especially where they affect reliability or involve unfairness, weigh heavily in favour of exclusion. Examples can include oppressive questioning, lack of caution, or illegal search and seizure.
• Nature and content of the evidence: Evidence of a defendant’s prior misconduct, particularly if it is only tangentially connected to the issues at trial, is likely to be more prejudicial than probative, especially if it paints the defendant in a negative light irrelevant to the current charge.
• Probative value vs prejudicial effect: A central consideration is whether the evidence is highly probative (makes a fact in issue significantly more likely) or if its potential to unfairly prejudice the court or jury outweighs that value.
• Reliability of the evidence: The court will consider whether there are reasons to doubt the accuracy or integrity of the evidence, such as unreliability due to how it was gathered or the witness's credibility.

Key Term: Probative Value
The extent to which a piece of evidence is logically capable of proving or disproving a fact that is in issue in the case.

Key Term: Prejudicial Effect
The risk that the evidence will improperly influence the tribunal of fact, leading them to convict or make findings because of prior conduct rather than on proper evidence relevant to the issue at hand.

Key Term: Adverse Effect on Fairness
A statutory test (also used in s.101(3) CJA 2003) requiring the judge or magistrates to decide whether admitting the evidence would create so much unfairness in the proceedings that it should not be admitted, balanced in light of all the circumstances.

The seriousness, relevance, and potential impact of the admission or exclusion of the evidence all form critical elements of the judicial assessment. Courts are especially cautious about permitting evidence that may lead the tribunal to convict on prejudicial (rather than probative) grounds.

Worked Example 1.1

David is on trial for theft. The prosecution seeks to admit evidence of a previous conviction for assault under gateway (d) CJA 2003, arguing this shows a propensity for dishonesty because David pleaded not guilty but was convicted after trial. The defence argues the assault conviction is irrelevant to dishonesty and highly prejudicial.

Answer:
The court will examine whether admitting the assault conviction risks having an adverse effect on the fairness of the proceedings. Assault is not particularly probative of dishonesty and may instead unfairly suggest to the jury that David is violent or generally criminal. As the probative value is low and the prejudicial effect high, the judge may exercise discretion under s 78 PACE 1984 to exclude the evidence, even though it would be technically admissible through gateway (d) of the CJA 2003.

Additional Considerations

While a single breach of PACE or its Codes does not automatically result in exclusion, substantial and deliberate or reckless breaches—especially those compromising a suspect’s rights (such as denial of legal advice or significant failures in disclosure)—increase the likelihood that exclusion will be appropriate. The court will take a proportional approach based on the seriousness of the breach and the risk of an unsafe conviction.

Exclusion under s 101(3) CJA 2003

One of the most significant safeguards in the CJA 2003 is found in section 101(3), which applies specifically where bad character evidence is sought to be admitted via gateway (d) (propensity to commit offences of the kind charged or to be untruthful) or gateway (g) (defendant has attacked another’s character). The power to exclude under s 101(3) is mandatory: the court must not admit such evidence if its admission would have such an adverse effect on the fairness of proceedings that evidence ought not to be admitted.

Key Term: Mandatory Exclusion
Where legislation (here, s.101(3) CJA 2003) directs the court that exclusion of evidence is not discretionary, but obligatory if the exclusionary test is satisfied.

Section 101(3) provides the primary statutory protection against unfair prejudice from bad character evidence admitted to show propensity or following an attack on another’s character. Unlike s 78 PACE 1984, the language imposes a duty on the court: if, on application by the defendant, the court finds the test is met, it must exclude the evidence.

Key Term: Gateway
Refers to one of the statutory bases under s.101(1) CJA 2003 by which bad character evidence may be admitted (gateways a–g).

Comparison with s 78 PACE 1984

While the wording of the tests is substantively similar—both emphasize the adverse effect on fairness—the operation is procedurally and substantively distinct:

• Under s 78 PACE 1984, exclusion is a matter of judicial discretion ("may refuse to allow evidence…").
• Under s 101(3) CJA 2003, exclusion is mandatory ("must not admit…"), provided the conditions are satisfied and the application is properly made in relation to gateways (d) or (g).

In all other gateways (a, b, c, e, f), the exclusionary power remains discretionary via s 78 PACE 1984 or the court’s common law powers.

It is important to note that evidence introduced by the defendant voluntarily (gateway (b)), agreed by all parties (gateway (a)), or necessary for explanation or to correct a false impression (gateways (c), (e), or (f)) is generally not scrutinised as heavily for prejudice; the rationale being that the defendant is not unfairly or involuntarily prejudiced in the same way.

Factors Considered under s 101(3)

The core statutory guidance for courts considering exclusion under s 101(3) is found in s 101(4):

• The amount of time elapsed since the prior conduct (older convictions, particularly from youth or where there has been a long gap in offending history, are less likely to be admitted if their probative value is outweighed by risk of prejudice).
• The similarity between past and present offences (more probative if highly similar in circumstance, intent, or means).
• The nature and number of previous convictions (single, minor, or irrelevant past offences less probative).
• The risk that the tribunal of fact may give disproportionate weight to the prior conduct, fostering prejudice or confusion, especially if the tribunal could be distracted from the issues central to the present trial.
• Whether the defendant has already provided an explanation for the prior behaviour, such as admitting guilt and showing remorse, which may limit the probative value of the evidence.
• The overall balance between probative value and prejudicial effect, always applying the fairness test in light of Article 6 ECHR.

Worked Example 1.2

Sarah, aged 30, is charged with shoplifting. The prosecution seeks to admit a single conviction for theft when she was 15 (received a conditional discharge). The defence applies to exclude the conviction under s 101(3) CJA 2003.

Answer:
The court will consider Sarah’s conviction in context: it is 15 years old, relates to conduct as a juvenile, and is her only previous conviction. The conviction is less likely to demonstrate a present propensity for theft, and the risk of unfair prejudice (the jury relying on history rather than present facts) is significant. The mandatory exclusionary rule applies—if admitting the conviction poses an adverse effect on fairness, the court must exclude the evidence.

Worked Example 1.3

The prosecution alleges Ben, on trial for burglary, has a series of previous burglary convictions, but the most recent is 20 years old, with unrelated offending in the interim. Defence objects under s.101(3).

Answer:
Here, the age, gap, and lack of recent, similar offending reduces the conviction’s probative value. The risk is that the tribunal might unduly weigh historical misconduct, contrary to the interests of justice. Applying s 101(3) with reference to s 101(4), the court is likely to conclude that fairness requires exclusion.

Additional Notes

When exercising powers under s 101(3), courts must be satisfied that exclusion is necessary to avert real and not merely speculative unfairness. Completion of a reasoned judgment is required, and the duty is engaged only on application by the defence; a judge may not raise s 101(3) exclusion on their own motion except to achieve a fair trial.

Procedural Matters

All applications to admit or exclude bad character evidence are governed by strict procedural rules. The Criminal Procedure Rules 2020, Part 21, set out requirements for advance notice, the form of applications, the timeline, and the provision of detailed particulars about the prior misconduct relied upon.

• A party seeking to adduce bad character evidence must usually serve written notice within 10 business days (Crown Court) or 20 business days (Magistrates’ Court) of a not-guilty plea.
• The notice must specify the facts, the method by which the facts will be proved (such as certified conviction), and the gateway relied upon.
• If the opposing party wishes to resist admission, they must respond within 10 business days of notice, stating reasons for objection, and—where appropriate—identify factual inaccuracies, alternative admissions, or grounds for exclusion (including under s.101(3) or s.78).
• Applications to exclude are usually considered by the judge (Crown Court, in absence of the jury) or magistrates (Magistrates’ Court), often at a pre-trial hearing; applications can be renewed just before evidence is adduced.
• Rulings must be reasoned, and the tribunal should specify, in open court, the reasons for granting or refusing exclusion.
• If exclusion is sought on s 78 PACE grounds, argument must focus on the fairness of the proceedings, usually referencing concrete breaches of procedure or recognisable prejudice.
• The burden of establishing unfairness rests, in practice, with the party objecting to admission, but the ultimate question is objective: would a fair-minded tribunal believe that the evidence should not be received?

Fair Trial and Article 6 ECHR

The right to a fair trial under Article 6 of the European Convention on Human Rights supports all exclusionary powers in English criminal procedure. The controlling test remains whether the proceedings as a whole, including the treatment of prior misconduct or allegations, allow the accused a fair and impartial hearing. Courts are alert to breaches of ECHR rights, especially when bad character or prior allegations are used to bolster a weak prosecution case. The presence or absence of judicial directions to the jury on the use of such evidence, and the effectiveness of defence representation, are considered significant.

Key Term: Article 6 ECHR
The guarantee in the European Convention on Human Rights of a fair and public hearing within a reasonable time, including minimum rights for anyone charged with a criminal offence, such as the presumption of innocence and the right to defend oneself.

Other Considerations

• Overlap with Other Exclusionary Powers: The operation of s 101(3) CJA 2003 is not mutually exclusive with section 78 PACE 1984. Where both could apply, the court must exercise caution and ensure the stricter (in this case, mandatory) test is properly applied in priority.
• Spent Convictions: Under most circumstances, spent convictions (as defined by the Rehabilitation of Offenders Act 1974) should not be admitted as evidence of bad character unless statute otherwise provides or the interests of justice require. The court always retains general discretion to prevent unfairness arising from the use of spent convictions.
• Good Practice: Where the court admits bad character evidence, careful and tailored judicial directions to the jury are necessary, making clear its limited relevance and reminding the tribunal not to convict the defendant solely on past wrongdoing.
• Misuse and Prosecution Conduct: The prosecution should not rely on bad character evidence as a substitute for proof of the present charge. Admitting such evidence, especially under gateways (d) and (g), is always exceptional and the court should consider alternative routes to proof.

Key Point Checklist

This article has covered the following key knowledge points:

• The court has both discretionary (s.78 PACE 1984) and mandatory (s.101(3) CJA 2003) powers to exclude bad character evidence.
• Discretionary exclusion under s 78 PACE 1984 applies to all prosecution evidence but is especially relevant to bad character evidence admitted under CJA 2003 gateways (a), (b), (c), (e), or (f).
• Mandatory exclusion under s 101(3) CJA 2003 applies to bad character evidence sought through gateways (d) (propensity) and (g) (attack on another's character), and the court must exclude if fairness is compromised.
• The core test in all exclusionary decisions is the comparative weighing of probative value versus prejudicial effect, with particular regard to the fairness of proceedings and the defendant’s right to a fair trial (Article 6 ECHR).
• Courts must have regard to the age and nature of prior misconduct, its relevance, the seriousness of prejudice, and the overall context of the trial.
• Strict procedural rules ensure that parties and the court are properly informed, and that exclusion applications are resolved before evidence is presented to the tribunal of fact.
• Judicial directions and clear reasoning are essential where prior misconduct is admitted, to safeguard against unfair prejudice.

Key Terms and Concepts

• Section 78 PACE 1984
• Bad character evidence
• Probative value
• Prejudicial effect
• Adverse effect on fairness
• Mandatory exclusion
• Gateway
• Article 6 ECHR