The evidence that is relevant in a proceeding is evidence that, if it were accepted, could rationally affect (directly or indirectly) the assessment of the probability of the existence of a fact in issue in the proceeding: Evidence Act ss.55(1), see further ss.55-58; DPP Massey (a Pseudonym)  VSCA 30; MA v R  VSCA 20. Evidence which is irrelevant is inadmissible. Relevant evidence is not necessarily admissible. Various rules of evidence might apply to make it inadmissible.
> Separate jury trials of charges against one accused
version 21 January 2016
The document which contains the charges for a County Court or Supreme Court criminal case is known as the indictment (formerly known as presentment). A trial can be of only one indictment but more than one charge can be upon an indictment where the law permits it.
Joinder of counts against one accused within a single indictment
An indictment may contain charges for related crimes against the same accused: Criminal Procedure Act Schedule 1 Rule 5. Related crimes means crimes that are founded on the same facts or form, or are part of, a series of crimes of the same or a similar character: Criminal Procedure Act s.3. Sameness or similarity includes a feature which in all the circumstances of the case enables the crimes to be described as a series; the policy is to enable the joinder of charges which may be "properly and conveniently" dealt with together: R v Spina  VSCA 319; R v McLean  VSCA 217, (2000) 2 VR 118. The charges will be founded on the same facts if for instance the subsidiary charge could not have been alleged but for the facts that gave rise for the primary charge. Whether a series of crimes is of same or similar character depends upon regard to law and the facts. It is not necessary that the evidence relating to one charge be admissible upon another charge: R v Papamitrou VSCA 12, (2004) 7 VR 375; R v Cogley  VSCA 123,  3 VR 366. It is enough if they have, for example, a common genesis or, on some other basis, may fairly be treated for the purposes of the trial as linked or associated, rather than separate or discrete: R v McLean. There is not to be overly narrow approach: R v Renzella VICSC 37.
Complaint that counts have been included to impermissible extent are uncommon. Successful complaint would ordinarily result in prosecution filing over separate indictments, but in face of prosecution intransigence, remedy would be judicial quashing of the indictment.
Judicial power to order separation (severance) of trials of charges against one accused
Where charges are properly joined in a single indictment, there remains a judicial power to order separate trials of charges. The test is different to that in Schedule 1 which permits joinder in the same indictment document. Thus it not uncommonly occurs that a court finds joinder in the same indictment document proper but nevertheless in exercise of the judicial power orders separate trials. The judicial power is now provided by Criminal Procedure Act s.193; DPP v Lamb (a pseudonym)  VSCA 307. There is to be separation where an accused may be prejudiced because the accused is charged with more than one crime in the same indictment or for any other reason it is appropriate to do so. Whilst not identical to previous provision, the substance is sufficiently close to suppose the guidance offered by previous cases remains.
On the judicial power to order separate trials, see R v TJB  4 VR 621 per Callaway JA. "1. A presentment should always be severed where that is both desirable and practicable in order to ensure a fair trial. It is for defence counsel to persuade the judge that that is so..... 2. One aspect of a fair trial is the taking of reasonable steps to prevent a jury from misusing evidence. That is not limited to propensity evidence... 3. It is usually to be assumed that the jury will comply with any directions they are given by the judge. A fair-minded lay observer takes that very factor into account in considering whether a trial is fair: cf. Webb v R  HCA 30, (1994) 181 CLR 41 at p.55. 4. There are nevertheless cases where the risk of prejudice is unacceptable. It will often be found that that is so in the case of crimes of an unnatural character or crimes that arouse strong emotions or excite revulsion. 5. There is also a greater risk that a direction will be ineffectual if evidence in relation to one complainant is probative in relation to another but either the Crown does not rely on it for that purpose or the judge rules that it is inadmissible because of prejudice." See also Bui v R  VSCA 404; R v Renzella VICSC 37.
The cross-admissibility of evidence of complainants is in most cases a powerful (although not necessarily dominant) factor influencing the exercise of power so as to refuse separate trials:R v INS VSCA 61;R v CHS VSCA 19, (2006) 159 A Crim R 560; R v Papamitrou VSCA 12, (2004) 7 VR 375. One instance of cross-admissibility is as tendency or coincidence evidence under Evidence Act 2008.
Depending on the sort of case, and not infrequently in cases of commercial fraud, it is enough for joint trial that crimes or groups of crimes have a common genesis or are otherwise linked and associated by commonality of parties or transactions: R v Heinze VSCA 124; R v McLean  VSCA 217, (2000) 2 VR 118.
It is not necessarily reason for separate trial that there is a mix of reverse onus and normal onus counts: McLean.
For alleged sex crimes with separate victims, there is additional provision: Criminal Procedure Act s.195: (1) In this section - sexual crime includes an crime to which clause 1 of Schedule 1 to the Sentencing Act 1991 applies. (2) Despite section 193 and any rule of law to the contrary (other than the Charter of Human Rights and Responsibilities), if in accordance with this Act 2 or more charges for sexual crimes are joined in the same indictment, it is presumed that those charges are to be tried together. (3)The presumption created by subsection (2) is not rebutted merely because evidence on one charge is inadmissible on another charge.
The provision (and its predecessor) addresses a former practice (e.g. Hoch v R  HCA 50, (1988) 165 CLR 292; De Jesus v R  HCA 65, (1986) 61 ALJR 1) whereby severance was almost automatically granted: R v TJB  4 VR 621; GBF v R  VSCA 135; R v GAE  VSCA 18, (2000) 1 VR 198; R v KRA VSCA 157,  2 VR 708. Where the evidence on one count is inadmissible upon another, if there is a reason due to the prejudice to the accused in sexual crimes, coupled with a doubt about misuse of the evidence, separate trials are to be ordered where sought.
> Separate jury trials of one accused from another
version 11 June 2017
There must be separate trials if the prosecution has made the accused subject of separate indictments: R v Scott  VicSC 213; R v Landy  VicLawRp 14,  VLR 73. A State indictment and Commonwealth indictment though may proceed jointly provided they are drawn and signed as a single document: R v Nicola  VicRp 86,  VR 1040.
Joinder of more than one accused within a single indictment
An indictment may contain charges for related crimes against different accused: Criminal Procedure Act Schedule 1 Rule 5. Related crimes are crimes that are founded on the same facts or form, or are part of, a series of crimes of the same or a similar character: Criminal Procedure Act s.3.
If the prosecution wishes to join accused within a single indictment and meets the test, a question arises whether the charges should be joint or separate. Each crime must be subject of a separate charge: Criminal Procedure Act s.195 Schedule 1 Rule 5(2); R v Scalia  VicRp 22,  VR 200. A single crime may, however, have joint participants: see Complicity atnotes 1. Only where this is so is the joinder to be in the same count.
Any persistence of the prosecution with a indictment joining accused in circumstances not permitted by law should result in quashing the indictment or an order for stay.
Judicial power to order severance of trials of one accused from another
Where there is joinder of more than one accused in a single indictment as permitted by law, there remains a judicial power to order severance of the trials of accused: Criminal Procedure Act s.193; Mwamba v R  VSCA 338; Destanovic v R  VSCA 113; R v Alexander and McKenzie VSCA 183, (2002) 6 VR 53; R v Debs and Roberts  VSCA 66. The test is whether a trial with the co-accused would prejudice the fair trial of the accused; or for any other reason it is appropriate to do so.
An application for severance, which need not necessarily be made before plea, is to be determined upon the material then before the court which ordinarily will be the depositions and the attached exhibits: R v Demirok  VicRp 19,  VR 244. If not initially successful, the application may be renewed whenever fresh circumstances emerging in the course of the trial so justify.
Some factors supporting an application for judicial severance 1. Evidence admissible against a co-accused but inadmissible and prejudicial against the other accused: R v Guthrie and Nuttal VSCA 192; R v Murphy VSCA 23; R v Jones and Waghorn VicSC 447, (1991) 55 A Crim R 159; R v Demirok VicRp 19,  VR 244. Given that the jury may be warned against using this kind of inadmissible evidence these cases have suggested this factor to be weak, cf R v Lam VSCA 109; Destanovic v R  VSCA 113 (appeal ground against joint trial succeeded by majority due to jury direction endorsing possible use of inadmissible evidence). The factor has special force in some conspiracy cases: prima facie however, conspirators should be tried together: Fattal v R  VSCA 276; R v Darby HCA 32, (1982) 148 CLR 668. Another example is similar fact evidence against co-accused inadmissible and prejudicial against applicant such as held in the circumstances of R v Alexander and McKenzie should have caused separate trial. 2. Expectation of a defence to be offered by a co-accused which is antagonistic to the applicant. Examples are the giving of implicatory evidence against the applicant: R v Teitler  Vic Rp 54,  VR 321, and the giving of propensity evidence against the applicant, though given that a jury may be warned against misuse, the factor is weak: R v Gibb and McKenzie VicRp 78, 2 VR 155. On the warning today see Jury Directions Act 2015 sections.25-30. 3. Susceptibility of applicant to an attack upon character if giving evidence against co-accused: R v Ditroia and Tucci VicRp 28,  VR 247. 4. Expectation that accused has evidence exculpatory of the applicant which would be given upon separate trial: R v Demirok above. 5. Relative seriousness of the allegations against the applicant: R v Demirok; R v Gibb and McKenzie at 162.
Some factors opposing an application for judicial severance 1. Significant inconvenience to be caused in terms of court time and public expense: R v Ditroia and Tucci above. 2. Joint participation: R v Guthrie and Nuttal VSCA 192; R v Ditroia and Tucci (only in exceptional cases that accused persons charged with joint or related crimes arising from the one transaction or series of transactions will be permitted to stand trial separately). 3. The prospect of inconsistent verdicts upon separate trials: R v Ditroia and Tucci. 4. Inconvenience to witnesses: R v Demirok  VicRp 19,  VR 244.
> Silence of accused or selective response
version 23 May 2017
Right to silence of person in custody: Crimes Act s.464A(3). Silence of an accused in the investigative context, where a caution is administered, is not an inculpatory circumstance:Evidence Act s.8. (It is to be remembered though that exculpatory answers will be one means of getting a defence account to a jury or other tribunal of fact. And inculpatory answers may support mitigating factors on sentence, especially upon plea of guilty.)
The rule has long earlier common law history. In RPS v R HCA 3, (2000) 199 CLR 620, the High Court (per Gaudron ACJ, Gummow, Kirby and Hayne JJ) gave the reason for it as follows. "The 'right to silence' derives from the privilege against self-incrimination. That privilege is one of the bulwarks of liberty. History, and not only the history of totalitarian societies, shows that all too frequently those who have a right to obtain an answer soon believe that they have a right to the answer that they believe should be forthcoming. Because they hold that belief, often they do not hesitate to use physical and psychological means to obtain the answer they want. The privilege against self-incrimination helps to avoid this socially undesirable consequence.
The privilege exists to protect the citizen against official oppression."
However, (i) a suspect who would have been expected to respond in all the circumstances does not do so, (ii) the right to silence has not been referred to and (iii) no statutory provision is breached, then silence or selective response may be incriminating:Xypolitos v R VSCA 339; R v MMJ  VSCA 226, (2006) 166 A Crim R 501; R v Alexander  Vic Rp 58,  2 VR 249. Also, selective response after reference to right to silence may be incriminating: Woon v R HCA 23, (1964) 109 CLR 529; R v Barrett  VSCA 95, (2007) VR 240; R v McNamara VicRp 68,  VR 855. Since it is not incriminating where silence is by reason of using right to silence, this kind of argument is uncommonly attempted by prosecution or permitted. However, for example, an accused's conscious omission of events from a detailed account provided may be a basis for drawing the inference of a consciousness of guilt and, if an accused makes a positive statement to police that he cannot remember an event, or that he has no recollection of it or the details of it, it may well constitute evidence which in combination with other evidence is capable of amounting to evidence of consciousness of guilt: R v Cuenco  VSCA 41, (2007) 16 VR 118.
There is also a right to silence at trial: Jury Directions Act 2015 as.42 as follows. The trial judge, the prosecution and defence must not say, or suggest in any way, to the jury that, because an accused did not give evidence or call a particular witness, the jury may
(a) conclude that the accused is guilty from that fact; or (b) use the failure of the accused to provide an explanation of facts, which must be within the knowledge of the accused, to more safely draw an adverse inference based on those facts which, if drawn, would prove the guilt of the accused; or (c) draw an inference that the accused did not give evidence or call a witness because that would not have assisted his or her case.
The right to silence at trial has long earlier common law history. The reason mainly given for it is the accusatorial nature of a criminal trial, the principle that the onus of proving a criminal crime lies upon the prosecution and that in discharging that onus it cannot compel the accused to assist it in any way: X7 v Australian Crime Commission  HCA 29, (2013) 248 CLR 92; Environment Protection Authority v Caltex Refining Co Pty Ltd  HCA 74; (1993) 178 CLR 477.
> Tendency, coincidence and context evidence
In Victoria, several rules deal with the exclusion and admissibility of evidence that an accused has committed wrong-doing other than that subject of the charge.
In Victoria, and elsewhere in Australia, there always have been such rules for instance permitting in certain limited conditions tendency and coincidence evidence. These have applied to all types of cases including alleged child abuse. For Victoria, the current rules and their interpretation are dealt with below.
The tendency rule
The tendency rule is that evidence of the character, reputation or conduct of a person, or a tendency that a person has or had, is not admissible to prove that a person has or had a tendency (whether because of the person's character or otherwise) to act in a particular way, or to have a particular state of mind unless the court thinks that the evidence will, either by itself or having regard to other evidence adduced or to be adduced by the party seeking to adduce the evidence, have significant probative value: Evidence Act s.97(1). Probative value of evidence means the extent to which the evidence could rationally affect the assessment of the probability of the existence of a fact in issue: Evidence Act Dictionary.
The leading authority in interpreting in this context "significant probative value" is High Court case Hughes v R  HCA 20 (concerning NSW equivalent section but explicitly addressing also Victoria), see also Bauer (a Pseudonym)
v R (No2)  VSCA 76. Amongst other matters, the majority in Hughes held as follows. Where evidence is adduced to prove the identity of the offender for a known crime, the probative value of tendency evidence will almost certainly depend upon close similarity between the conduct evidencing the tendency and the crime. Different considerations may inform the probative value of tendency evidence where the fact in issue is the occurrence of the crime. The assessment of whether evidence has significant probative value involves consideration of two interrelated but separate matters. The first matter is the extent to which the evidence supports the tendency. The second matter is the extent to which the tendency makes more likely the facts making up the charged crime. Where the question is not one of the identity of a known offender but is instead a question concerning whether the crime was committed, it is important to consider both matters. By seeing that there are two matters involved it is easier to appreciate the dangers in focusing on single labels such as "underlying unity", "pattern of conduct" or "modus operandi". The open-textured, evaluative task remains one for the court to undertake by application of the same well-known principles of logic and human experience as are used in an assessment of whether evidence is relevant.
A factor diminishing the extent to which the evidence supports the tendency is where the sole source of the evidence is the complainant: Bauer v (a Pseudonym)  VSCA 76..
In a case involving multiple sexual complainants, a reasonable possibility that there has been concoction or contamination between them would be a matter diminishing the extent to which the evidence supports the tendency: .Bauer v (a Pseudonym)  VSCA 76; (did not arise in Hughes v R  HCA 20 and not addressed by majority, Gageler J, dissenting on the result, obiter, would have dealt thus with any concoction or contamination point).
Where the court thinks the tendency rule otherwise operates to admit the evidence, it is to be excluded where the prejudicial effect it may have on the defendant substantially outweighs its probative value: Evidence Act s.101(2).
By the majority in Hughes v R  HCA 20, the reception of tendency evidence in a criminal trial may occasion prejudice in a number of ways. "The jury may fail to allow that a person who has a tendency to have a particular state of mind, or to act in a particular way, may not have had that state of mind, or may not have acted in that way, on the occasion in issue. Or the jury may underestimate the number of persons who share the tendency to have that state of mind or to act in that way. In either case the tendency evidence may be given disproportionate weight. In addition to the risks arising from tendency reasoning, there is the risk that the assessment of whether the prosecution has discharged its onus may be clouded by the jury's emotional response to the tendency evidence. And prejudice may be occasioned by requiring an accused to answer a raft of uncharged conduct stretching back, perhaps, over many years."
Consideration of the tendency rule has most often occurred in cases alleging crimes of child sexual abuse especially with multiple complainants. Also, in homicide and other violence cases, the reception of evidence of hostile relationship falls for consideration under the tendency rule: Azizi v R  VSCA 205; Middendorp v R  VSCA 47.
The coincidence rule
The coincidence rule is that evidence that two or more events occurred is not admissible to prove that a person did a particular act or had a particular state of mind on the basis that, having regard to any similarities in the events or the circumstances in which they occurred, or any similarities in both the events and the circumstances in which they occurred, it is improbable that the events occurred coincidentally unless the court thinks that the evidence will, either by itself or having regard to other evidence adduced or to be adduced by the party seeking to adduce the evidence, have significant probative value: Evidence Act s.98(1). There is required to be similarity by way of underlying unity, or a common modus operandi, or a pattern of conduct: CGL v DPP  VSCA 26, (2010) 24 VR 486. For instance it may lie in similarity of events: Harris (a pseudonym) v R  VSCA 112. Or for instance it may lie in the existence of a relationship which uniquely links the accused person with two or more victims of similar crimes: CW v R  VSCA 288. Features of the alleged offending which reflect circumstances outside the accused's control are not to be treated as relevant similarities for this purpose, and the possibility of concoction or contamination should be considered: BSJ v R  VSCA 93, (2012) 35 VR 475.
Where the court thinks the coincidence rule otherwise operates to admit the evidence, it is, as with tendency evidence (above) to be excluded where the prejudicial effect it may have on the defendant substantially outweighs its probative value: Evidence Act s.101 (2).
The context rule
Context evidence is evidence of other misconduct which places the evidence relating to a charged crime in a more complete and realistic context, for instance to correct an impression a charged crime was an inexplicably isolated incident with the complainant: DPP v Martin (a pseudonym) VSCA 219;Benson v R VSCA 51.
The rule from O'Leary's case is probably classifiable as within the context rule. With a charge based on of one of the violence crimes, it gives evidence of other violence admissibility where it is part of a transaction of which the violent crime forms an integral part and cannot be truly understood and isolated from it: Hothnyang v R  VSCA 64; O'Leary v R  HCA 44, (1946) 73 CLR 566.
Before a charge of crime against Victoria law can succeed in a Victoria court, there must be Victoria territorial jurisdiction or Victoria extra-territorial jurisdiction. It seems that where an crime is brought beyond Victoria territorial jurisdiction or Victoria extra-territorial jurisdiction, the Victoria court has jurisdiction but no Victoria crime is proved and the case is therefore is to be dismissed: McDonald v Bojkovic  VicRp 33,  VR 387. Where there is a factual contest upon which territorial or extra-territorial jurisdiction would depend, proof is on the balance of probabilities: Thompson v R HCA 30, (1989) 169 CLR 1; HA v R  VSCA 77.
There is territorial jurisdiction only where an accused commits in Victoria all the elements of a Victoria crime, or if there is an element recognised at common law as the gist of the crime, that element (this second limb now of rare or lacking example in Victoria as statute has largely displaced common law). With a continuing crime, there can be territorial jurisdiction notwithstanding that the crime is also committed elsewhere.
There is some extra-territorial jurisdiction for common law crimes. The main examples of common law crimes remaining now in Victoria are some homicide crimes, common assault and conspiracy to defraud. There is statutory provision for trial for murder or manslaughter in Victoria where death or cause of death only happens in Victoria: Crimes Act s. 9. For common law crimes (and statutory crimes) there is some extra-territoriality for coastal waters of Victoria and the seas beyond: Interpretation of Legislation Act s.57; Crimes at Sea Act. Absent any statutory provision, there is extra-territoriality for common law crimes where an accused, though committing in Victoria not all or none of the elements of a Victoria crime, commits within Australia that which if all the elements were committed in Victoria would be a Victoria crime, and there is nexus to Victoria. The requirement of nexus is to be liberally applied, a real connection with the jurisdiction will suffice (sometimes called "real connection" nexus). Leading authority is Lipohar v R HCA 65, (1999) 200 CLR 485 (concerned South Australian case alleging common law conspiracy to defraud) and by the joint judgment of Gaudron, Gummow and Hayne JJ, the main underlying reasoning is that throughout Australia the common law has unity (other judgments did not go this far, Gleeson CJ finding it sufficient there was to be harm within the State in which case was heard, Callinan J finding real connection enough but refraining from necessarily extending the principle beyond conspiracy cases; Kirby J dissenting). With common law crimes, where the aforesaid commission is at least partly outside Australia, it seems the required nexus is stricter, being actual or threatened breach of the peace within the State where the case is heard even if the accused be outside that State or Australia: Truong v R HCA 10, (2004) 223 CLR 122 accepting Privy Council case Liangsiriprasert v United States UKPC 31,  1 AC 22 (sometimes called "terminatory" nexus).
Any extra-territorial jurisdiction for statutory crimes depends upon statute. Off-shore and at sea provisions are referred to above. Also, there are for Victoria some express creations of extra-territoriality for particular statutory crimes, such as by Crimes Act sections 70B, 80A, 90, 181, 252, 317A, 321A and 321O; Terrorism (Community Protection) Act s.4A. In accordance with general principles of statutory interpretation, there can for statutory crimes also be implied creations of extra-territoriality, though there at least used to be a rebuttable presumption against it for penal provision: Thompson v R  HCA 30, (1989) 169 CLR 1 (per Brennan J); McDonald v Bojkovic  VicRp 33,  VR 387. In Truong v R HCA 10, (2004) 223 CLR 122, where some of the crimes were statutory and there was no express provision for extra-territoriality, the court accepted that the crimes including the statutory crimes had extra-territoriality, the nexus being actual or threatened breach of the peace within Victoria even if the accused be outside Victoria or Australia. Stalking pursuant to Crimes Act s.21A is an example of a statutory crime held to have impliedly extra-territorial application of even no more than "real connection" nexus: DPP v Sutcliffe  VSC 43 (Gillard J); leave to appeal declined without ruling on the issue Sutcliffe v DPP  VSCA 34.
Alleged accomplices as witnesses. Provision for warning to jury concerning evidence given in a criminal proceeding by a witness, being a witness who might reasonably be supposed to have been criminally concerned in the events giving rise to the proceeding: Jury Directions Act 2015 ss.31(c), 32;Andelman v R  VSCA 25, (2013) 38 VR 659. Additional warning is ordinarily given where the witness has received indemnity or sentencing benefits.
Oral evidence of questioning by an investigating official (within the meaning of the Evidence Act) of an accused where the questioning has not been acknowledged by the accused: Jury Directions Act 2015 s.31(e).
Evidence might be unreliable for a reason other than it fits within one of the Jury Directions Act 2015 s.31 categories which are merely inclusive: Hudson (a Pseudonym) v R  VSCA 122. An example is the common law "Faure warning" for a tainted witness such as one not of the kind who might reasonably be supposed to have been criminally concerned but nevertheless suspect: R v Strawhorn  VSCA 101; DPP v Faure  VicRp 87;  2 VR 497.
By Evidence Act s.164, corroboration requirements are abolished. It is not necessary that evidence on which a party relies be corroborated. It is not necessary that the judge (a) warn the jury that it is dangerous to act on uncorroborated evidence or give a warning to the same or similar effect; or (b) give a direction relating to the absence of corroboration.
Children as a class are not unreliable witnesses: Jury Directions Act 2015 s.33. A jury may be directed that the collective experience of the courts is that the age of a witness is not determinative of his or her ability to give truthful and accurate evidence: CMG v R  VSCA 416. As a particular application of the need to warn concerning any witness who is potentially unreliable, warning is required on a child who in a particular case is potentially unreliable.
Grant is discretionary: R v Bertrand VSCA 182, (2008) 20 VR 222, 229; R v Rowley VicSC 330,(1986) 23 A Crim R 371. Need for significant issue to be tried: R v Callaghan VSCA 209, (2001) 4 VR 79. Proof on voir dire is to prima facie standard for issues which would remain for the jury: Wendo v R HCA 19, (1963) 109 CLR 559. Where the voir dire issue is one for final determination by the judge, it seems balance of probabilities is the standard: R v Browne-Kerr VicRp 7,  VR 78.Upon whether alleged confession should be received, guilt not to be subject of cross-examination by Wong Kam-ming v R  AC 247 though the force of this authority in Victoria is questionable: R v Tofilau  VSCA 40, (2006) 13 VR 28.
Children as witnesses: Ward (a Pseudonym) v R  VSCA 37. For alleged sexual crimes, violent crimes and certain others, there are provisions for persons under 18 or with a cognitive impairment for the person giving evidence including use of past video-or aural recorded interview known as VARE: Criminal Procedure Act ss.366-389; Martin v R  VSCA 377.
Where a witness available to prosecution is not called, the judge in some circumstances may inform the jury that it may conclude that the witness would not have assisted the prosecution's case: Jury Directions Act 2015s.43. However this is not so where a witness available to defence is not called and the judge in some circumstances may direct the jury to this effect: see further Jury Directions Act 2015 s.44.
Use of document to revive memory in court: A police officer, if specified conditions are met, may give evidence in chief for the prosecution by reading or being led through a written statement previously made by the police officer: Evidence Act s.33. For other witnesses, leave may be granted to use a document to revive memory in court: Evidence Act s.32. It also permitted where the witness by time of giving evidence has no independent recollection of the events. R v Anders VSCA 7, (2009) 193 A Crim R 202; R v Alexander  VicRp 74,  VR 741.