Published 10 days ago7 min read

Admissibility of Evidence: Relevance, Admissibility & the Exclusionary Rules

Master the admissibility of evidence - relevance test, exclusionary rules, Section 35(5), and how to analyze whether evidence can be admitted in court.

Admissibility of Evidence: Relevance, Admissibility & Exclusionary Rules

Area of Law: Law of Evidence
Reading Time: 11 minutes

🎯 What Is Admissibility?

Admissibility determines whether evidence can be presented in court and considered by the judge/jury.

Two-stage test:

Is it relevant? (Does it make a fact in issue more/less probable?)
Is it admissible? (Does any exclusionary rule prevent its admission?)

Key principle: Evidence must be both relevant AND admissible to be considered.

📖 Stage 1: Relevance

Definition

Evidence is relevant if it:

Makes a fact in issue more or less probable than it would be without the evidence.

Test: Does the evidence have logical probative value?

Examples of Relevant Evidence

In a breach of contract case:

✅ Contract document (shows terms)
✅ Correspondence between parties (shows agreement)
✅ Proof of non-performance (shows breach)
❌ Defendant's unrelated business dealings (no logical connection)

In a negligence case:

✅ Eyewitness testimony (proves conduct)
✅ Expert opinion on standard of care (proves negligence)
✅ Medical records (proves harm)
❌ Defendant's previous charitable donations (no logical connection to negligence)

Levels of Relevance

Direct evidence — Directly proves fact in issue

Example: Eyewitness saw accused stab victim

Circumstantial evidence — Proves facts from which inference can be drawn

Example: Accused had motive, means, opportunity

Both are admissible if relevant.

📖 Stage 2: Admissibility

Even if relevant, evidence may be inadmissible due to exclusionary rules.

Key Exclusionary Rules

1. Hearsay Rule

Out-of-court statements tendered for truth of contents are inadmissible unless exception applies.

See our complete guide to hearsay.

2. Opinion Rule

General rule: Witnesses must testify to facts, not opinions.

Exceptions:

Expert opinion — Admissible if expert qualified and opinion within expertise
Lay opinion — Limited exceptions (e.g., "he looked drunk," "the car was speeding")

Why excluded? Court decides ultimate issues; witnesses provide facts.

3. Character Evidence Rule

General rule: Evidence of a person's character or propensity is inadmissible to prove they acted in accordance with that character.

Example: "The accused has 10 prior assault convictions" is inadmissible to prove he committed this assault (propensity reasoning forbidden).

Exceptions:

Accused's good character — Accused can lead evidence of good character
Rebuttal — If accused leads good character evidence, State can rebut
Credibility — Previous convictions may be used to attack credibility
Similar fact evidence — If striking similarities exist (rare)

4. Privilege

Certain communications are privileged and cannot be disclosed:

(a) Legal Professional Privilege

Communications between lawyer and client for purpose of legal advice
Absolute (even after death)

(b) Spousal Privilege

Spouse cannot be compelled to testify against spouse in criminal proceedings
Does not apply if spouse consents or crime against spouse

(c) Without Prejudice Communications

Settlement negotiations cannot be disclosed in court
Promotes settlement

(d) Self-Incrimination Privilege

Witness cannot be compelled to answer if answer may incriminate them
Constitutional protection (Section 35(3)(j))

5. Unconstitutionally Obtained Evidence

Section 35(5) Constitution:

"Evidence obtained in a manner that violates any right in the Bill of Rights must be excluded if the admission of that evidence would render the trial unfair or otherwise be detrimental to the administration of justice."

Test (from S v Tandwa 2008):

Was evidence obtained in violation of constitutional right?
If yes, would admission render trial unfair?
If yes, would admission be detrimental to administration of justice?

Factors:

Nature and seriousness of rights violation
Deliberate vs good faith violation
Availability of other evidence
Seriousness of offence
Need for evidence vs rights protection

Result: Court has discretion to exclude.

6. Improperly Obtained Evidence (Common Law)

Evidence obtained improperly (but not unconstitutionally) may be excluded if:

Obtained unfairly (e.g., trickery, deceit)
Admission would be prejudicial to accused
Public policy requires exclusion

Courts balance:

Seriousness of impropriety
Need for evidence
Availability of other evidence

🏛️ Key Cases

S v Tandwa (2008) — Unconstitutionally Obtained Evidence

Police searched accused's home without warrant, found drugs.

Held: Search violated Section 14 (privacy). Evidence excluded because admission would render trial unfair and be detrimental to administration of justice.

S v Hena (2006) — Confession Obtained Improperly

Accused confessed after police promised leniency.

Held: Confession inadmissible — obtained improperly, not free and voluntary.

Woji v Santam Insurance (1981) — Relevance

Court emphasized evidence must have logical probative value.

Irrelevant evidence wastes time and may confuse issues.

💡 Exam Tips & Application

How to Analyze Admissibility

Step 1: Is it relevant?

"The evidence is relevant because it makes it [more/less] probable that [fact in issue] occurred."

Step 2: Is there an exclusionary rule?

Check:

Step 3: Does an exception apply?

If exclusionary rule applies, consider exceptions (e.g., hearsay interests of justice test).

Step 4: Conclude

"The evidence is [admissible / inadmissible] because..."

Sample Exam Answer

Question:

"Police search accused's car without consent or warrant. They find drugs. Is the evidence admissible?"

Model Answer:

Relevance: The drugs are relevant — they make it more probable the accused possessed drugs.

Admissibility: The evidence was obtained unconstitutionally. Section 14 of the Constitution protects the right to privacy, including property searches. A warrantless search violates Section 14 unless justified (e.g., consent, exigent circumstances).

Section 35(5) Test (from S v Tandwa):

(1) Constitutional violation? YES — Section 14 violated.

(2) Would admission render trial unfair?

Serious rights violation (warrantless search)
Appears deliberate (no emergency)
Key evidence (prosecution's case depends on it)
BUT: Serious offence (drug trafficking)

(3) Detrimental to administration of justice?

Excluding evidence may let guilty person go free
BUT: Admitting rewards police misconduct, undermines rights

Balance: Court likely to exclude if violation was serious and deliberate. If good faith mistake or exigent circumstances, may admit.

Conclusion: Evidence is prima facie inadmissible under Section 35(5). Court has discretion to exclude if admission would render trial unfair or be detrimental to justice."

⚠️ Common Mistakes

❌ Mistake 1: Confusing Relevance with Admissibility

Wrong: "The evidence is relevant, so it's admissible."

Correct: "The evidence is relevant, but it may be inadmissible due to [exclusionary rule]."

❌ Mistake 2: Forgetting to State Why Evidence Is Relevant

Wrong: "The evidence is relevant."

Correct: "The evidence is relevant because it makes it more probable that [fact in issue] occurred."

❌ Mistake 3: Not Considering All Exclusionary Rules

Wrong: "It's not hearsay, so it's admissible."

Correct: "It's not hearsay, but it may be excluded under [another rule, e.g., privilege, opinion, character]."

❌ Mistake 4: Ignoring Constitutional Dimension

Wrong: "Evidence obtained illegally is always inadmissible."

Correct: "Evidence obtained unconstitutionally may be excluded under Section 35(5) if admission would render trial unfair or be detrimental to justice. Court has discretion."

🔗 Related Concepts

1. Weight vs Admissibility

Admissibility — Can evidence be considered?

Weight — How much credibility/probative value does it have?

Evidence may be admissible but have little weight (e.g., unreliable witness).

2. Burden of Proof

Once evidence is admitted, question becomes: Who bears burden of proving facts?

See our guide to balance of probabilities.

3. Judicial Notice

Court can take judicial notice of facts so well-known they don't need proof (e.g., "December is summer in South Africa").

📚 Further Reading

Legislation:

Constitution, Section 14 — Privacy
Constitution, Section 35(5) — Exclusion of unconstitutionally obtained evidence
Law of Evidence Amendment Act 45 of 1988

Cases:

S v Tandwa (2008) — Section 35(5) test
S v Hena (2006) — Improperly obtained confessions
Woji v Santam (1981) — Relevance

Textbooks:

Schwikkard & Van der Merwe, Principles of Evidence
Zeffertt, Paizes & Skeen, The South African Law of Evidence

🎓 Study Summary

Two-stage test:

Relevance — Does it make fact in issue more/less probable?
Admissibility — Is there an exclusionary rule?

Exclusionary rules:

Hearsay
Opinion
Character/propensity
Privilege
Unconstitutionally obtained (Section 35(5))
Improperly obtained

Exam approach:

State whether evidence is relevant (and why)
Identify any exclusionary rule
Consider exceptions
Conclude on admissibility

✅ Quick Revision Checklist

Can you define relevance?
Can you list the main exclusionary rules?
Can you apply the Section 35(5) test?
Can you distinguish relevance from admissibility?
Can you distinguish admissibility from weight?

Need help with an evidence problem? Ask in the Community Q&A and get expert feedback.

Tags: #admissibility #relevance #evidence #exclusionaryrules #section35 #privilege

Enjoyed this piece?

Subscribe to get more case analyses and study tips like this — delivered occasionally, never spam.