In deciding whether evidence is relevant, the trial judge is neither required nor permitted to make any assessment of whether the jury would or might accept that evidence, but must proceed on the assumption that it will be accepted: Adam v The Queen (2001) 207 CLR 96 at [22], [60]; R v Shamouil (2006) 66 NSWLR 228 at [60]–[62]. It is suggested that the same assumption should be made where the judge is also the tribunal of fact. The test of relevance — that the evidence could rationally affect (directly or indirectly) the assessment of the existence of a fact in issue in the proceeding — directs attention to the capability rather than the weight of the evidence to perform that task, but the issues of credibility or reliability may be such in the particular case that it is possible for the judge to rule that it would not be open to the jury to conclude that the evidence could perform that task: R v Shamouil at [62]–[63]; DSJ v R (2012) 215 A Crim R 349 at [8], [53]–[56].

The threshold test is whether there is a logical connection between the evidence and a fact in issue: Papakosmas v The Queen (1999) 196 CLR 297 at [81]. The definition of relevance in s 55 reflects the common law: Washer v Western Australia (2007) 234 CLR 492 at [5], n 4. The requirement that the capacity of the evidence to rationally affect the assessment of the evidence is significant, and it is necessary to point to a process of reasoning by which the evidence could do so: Washer v Western Australia at [5]; Evans v The Queen (2007) 235 CLR 521 at [23]. Where the effect of the evidence is so ambiguous that it could not rationally affect the assessment of the fact in issue, the evidence is irrelevant: Lithgow City Council v Jackson (2011) 244 CLR 352 at [26].

A majority of the High Court in BBH v The Queen (2012) 245 CLR 499 has endorsed the proposition that evidence is relevant and therefore admissible so long as it has probative value. This is so notwithstanding that it may ultimately be categorised by the tribunal of fact as carrying no weight: Heydon J at [97]–[104]; Crennan and Kiefel JJ at [152], [158]–[160]; Bell J at [194]–[197]. Moreover, the tribunal of fact is entitled to assess the particular piece of evidence by having regard to the whole of the evidence in the light of the issues at trial: Bell J at [196]. Where there is an issue regarding the authenticity of a document, it may still be admissible if it is relevant or arguably so. This is so as long as there is material from which its authenticity may reasonably be inferred. That material will include what may reasonably be inferred from the document itself: Australian Competition and Consumer Commission v Air New Zealand Ltd (No 1) (2012) 301 ALR 326.

The general proposition stated by French CJ (at [57] and [58]) that “equivocal” evidence is not relevant and should thus be rejected (see also Hayne J at [80]–[81], Gummow J at [61]) was not supported by the majority decisions: see Criminal Trial Courts Bench Book Special Bulletin 26.

In a criminal case, s 55 directs attention to the elements of the offence charged, the particulars of those elements and any circumstances which bear upon the assessment of probability; facts in issue are not limited to the ultimate issues, but include facts relevant to those issues: Smith v The Queen (2001) 206 CLR 650 at [7]. The prosecution may set out to establish that an accused had a motive to commit an offence charged. Motive may rationally affect the assessment of the probability of the existence of one or more of the elements of an offence; evidence that tends to establish motive, therefore, may rationally affect such assessment: HML v The Queen (2008) 235 CLR 334 at [5] (Gleeson CJ).

The evidence must affect the probability of the existence of the fact sought to be proved. In a case where it was alleged that the accused had acted in self-defence, evidence that the victim had previously carried a firearm did not go to the probability that he was carrying a firearm on the occasion in question: Elias v R [2006] NSWCCA 365 at [26]; although it would have been relevant to the issue of his tendency to carry such a weapon (at [31]); R v Cakovski (2004) 149 A Crim R 21 at [36], [56]–[57], [70] (see [4-1610]) doubted.

Observing how the accused walked or how he spoke certain words would be relevant to the identification of the accused as the person seen and heard by the witnesses, but dressing the accused in the clothing worn by the person seen by the witnesses gave no assistance to the jury in determining whether he was the person seen by the witnesses: Evans v The Queen, above, at [27].

Where evidence of identification depends on a photograph taken by a security camera, it is for the jury to determine whether the accused is shown in the photograph, and evidence by a police officer that he had made such an identification from the photograph cannot logically affect the jury’s task: Smith v The Queen, above, at [11]. A complainant who has no recollection of an alleged sexual assault cannot be asked whether her interview video recorded shortly after the event demonstrated that she had consented: R v TA (2003) 57 NSWLR 444 at [6], [24], [26].

The Law Reform Commission’s intention — that only a minimal logical connection between the evidence and the fact in issue was required, sufficient to make the fact in issue more probable or less probable than it would be without the evidence (ALRC Report 26, vol 1) — was accepted as the appropriate interpretation of s 55, in R v Clark (2001) 123 A Crim R 506 at [111]–[112]. Evidence is either relevant or it is not; no discretion falls to be exercised in determining relevance: Smith v The Queen at [6]; Phillips v The Queen (2006) 225 CLR 303 at [50].

The “probative value” of evidence and the “credibility” of a witness are defined in the Dictionary to the Evidence Act. Section 55(2) does not of itself make the credibility of a witness relevant to a fact in issue in the proceeding unless it is of such a nature as to tend rationally and logically to weaken confidence in the veracity of the witness: R v Slack (2003) 139 A Crim R 314 at [31]–[34].

The probative effect of telling a lie is logically the same in a civil case as it is in a criminal case: Barrett Property Group Pty Ltd v Carlisle Homes Pty Ltd [2008] FCA 375 (Heerey J) at [75]–[76].

If evidence is not relevant, it is not admissible: Smith v The Queen at [12].

This section raises the vexed question as to whether a miscarriage of justice may have occurred if no objection is taken to “irrelevant evidence”: see [4-0400] and also at [4-1630]. The better view is that “not admissible” means “not admissible over objection”, although in a criminal trial the judge has an overriding duty to ensure a fair trial and to prevent a miscarriage of justice: Perish v R [2016] NSWCCA 89.

Evidence relevant to the case against one of a number of defendants is relevant to the proceedings within the meaning of s 55, and its use against the other defendants may only be limited by the terms of s 136; the evidence is not unfairly prejudicial against another defendant within the meaning of s 136 only because it is not relevant to the case against that defendant, although it may be regarded as so prejudicial if the case is tried with a jury: Johnstone v State of NSW (2010) 202 A Crim R 422 at [102]–[103].

Whilst evidence relating to the prior sexual history of the complainant may be relevant, statutory proscriptions may make it inadmissible — see Criminal Trial Courts Bench Book at [5-100] and ff.

This provision is similar to the practice before the Evidence Act of admitting evidence subject to relevance: Nodnara Pty Ltd v Deputy Commissioner of Taxation (1997) 140 FLR 336 (Young J) at 338. Where the relevance of particular evidence is initially unclear, it remains appropriate under the Act for evidence to be admitted in a non-jury case subject to relevance, and for a ruling to be made as to its effect at the conclusion of the case: Merrylands Bowling, Sporting and Recreation Club Ltd v P & H Property Services Pty Ltd [2001] NSWCA 358 at [35].

The issue as to whether s 57 permits the issue of a document’s authenticity to be postponed until after its relevance has been determined has not yet been satisfactorily determined. In National Australia Bank Ltd v Rusu (1999) 47 NSWLR 309 (SC) at [19] et seq, Bryson J held that relevance depends on the authenticity of the evidence, and must be established before relevance can be determined. S Odgers, Uniform Evidence Law has argued (at [EA 57.120]) that, as s 57(1) requires only that it is “reasonably open” to make a finding of authenticity, the ruling in National Australia Bank Ltd v Rusu, above, is wrong. In Idoport Pty Ltd v National Australia Bank Ltd [2000] NSWSC 1250, Einstein J relied in part on s 57 as sanctioning a widening of the circumstances in which evidence may be admitted subject to relevance, but did not elaborate the basis for that view.

The Court of Appeal referred inconclusively to National Australia Bank Ltd v Rusu in Daw v Toyworld (2001) 21 NSWCCR 389 at [46], but with apparent approval in Trimcoll Pty Ltd v Deputy Commissioner of Taxation [2007] NSWCA 307 at [30]. In Trimcoll at [30], the Court of Appeal held that the relevance of a document in the particular proceedings may depend on the identity of its author, when it was created and whence it was extracted, whereas its authenticity depended on whether the document is what it purports to be; there is no entirely clear dividing line between questions of authenticity and identity and each may provide a basis for admissibility. National Australia Bank Ltd v Rusu was followed by Austin J in ASIC v Rich (2005) 216 ALR 320 at [116]–[119] and at [152] et seq. He emphasised that the question is, as the Law Reform Commission had stated (ALRC Report 26, vol 1, at [641]): could the evidence, if accepted, affect the probabilities?

In O’Meara v Dominican Fathers [2003] ACTCA 24, Gyles and Weinberg JJ (at [85]) expressed “considerable doubt” as to the decision in National Australia Bank Ltd v Rusu, but in the end (at [88]) they were satisfied on the evidence that the document in issue in that case was authentic, and they held that, by reason of its potential to be misleading or confusing, the document should have been rejected in the exercise of the general discretion afforded by s 135 (at [90]).

In Smith v The Queen (2001) 206 CLR 650 at [45], Kirby J said, in his dissenting judgment, that it was undesirable, as a matter of legal policy, and unnecessary in the terms of admissibility stated in s 55, “to set the hurdle of relevance too high”. In ASIC v Rich, above, (at [157]), Austin J accepted that this statement was not inconsistent with the test of relevance adopted by the majority judgment in Smith.

Section 57(2) (“Provisional relevance”) permits the use of evidence that a party to the proceedings is a member of a joint criminal enterprise for the purpose of determining whether or not he or she is in fact a member of that enterprise. The Law Reform Commission explained (at ALRC Report 26, vol 1, par 646 “Conspirators”) that such evidence — tendered on the basis that it is reasonably open to the tribunal of fact to find that he or she is a member of the enterprise — is not tendered for a hearsay purpose and thus is not caught by the hearsay provisions in the Act; cf Ahern v The Queen (1988) 165 CLR 87 at 93–94, 99–100; R v Masters (1992) 26 NSWLR 450 at 460–461. See also s 87(1)(c) (“Admissions made with authority”) at [4-0870].

See also s 183 of the statute, which permits any reasonable inferences to be drawn from a document where a question arises about the application of a provision of the statute in relation to that document.