5. Disclosure of unused material and defence statements

Question 1

Where can the stautory regime for disclosure of unused material be found?

Answer 1

Criminal Procedure and Investigations Act 1996

Question 2

Where is the regime in the CPIA used?

Answer 2

The statutory regime is compulsory in relation to cases on indictment, when it arrives in the crown court, up until the conclusion of the trial.

The regime is also compulsory to any summary trial, including in the youth court, except where the defendant has pleaded guilty, and is also applicable to cases where it is expected the defendant will plead not guilty.

Question 3

Is the CPIA the be all and end all for disclosure?

Answer 3

While the CPIA replaces the previous common law tests for disclosure in the cases it applies to, there may be some times where disclosure is still required outside of the statutory scheme because of common law.

Question 4

What is the essential question on disclosure for prosecutors?

Answer 4

The essential consideration for a prosecutor is whether disclosure of any material to the defence is required in accordance with the interests of justice and fairness.

Question 5

Does everything need to be disclosed at once?

Answer 5

No.

In fact, the CPIA envisages a staged approach to disclosure:

a. a duty on officers to record and retain all information/material that is relevant to the investigation

b. material which is relevant but not expected to be used should be provided to the prosecutor to review

c. the prosecution must apply the statutory test to that material, and disclose any material meeting that test, usually together with a schedule of all the other material recorded and retained.

d. the defence, in turn, have a duty to inform the prosecution of their case they will present at trial

e. the prosecution is under a continuing duty of disclose throughout proceedings

f. after service of defence statement and any further/failure to make disclose, an accused may make further applications for disclosure.

Question 6

When can an application for further disclosure be made?

Answer 6

Where a dispute arises about whether the prosecution should disclose certain unused material.

Question 7

What offences do the disclosure provisions of CPIA apply to?

Answer 7

Any alleged offence for which a criminal investigation began on or after 1 April 1997.

Question 8

Who is an investigator under the CPIA?

Answer 8

Any police officer involved in the conduct of a criminal investigation.

Question 9

Who is a disclosure officer under the CPIA?

Answer 9

The person responsible for examining material retained by the police during the investigation and for revealing material to the prosecutor.

Question 10

Who is the officer in charge of the investigation?

Answer 10

The police officer responsible for directing a criminal investigation, including ensuring that proper procedures are in place for recording information, retaining records of information and other material in the investigation.

Question 11

What does the CPIA code say must happen in regard to the persons carrying out disclosure roles?

Answer 11

The CPIA Code emphasises the need to retain clear records of the identities of the persons performing these roles; that they are carried out by suitably experienced individuals, independent of the investigation; and that the investigative process is tailored to the circumstances of each case.

Question 12

What information must investigators record?

Answer 12

Investigators must record, in a durable or retrievable form, all material which may be relevant to the investigation and which is not already recorded. This obligation to record includes negative information, e.g., the fact that a number of people present at a particular place and time saw nothing unusual

Question 13

Must investigators retain information?

Answer 13

Yes, the investigator is also responsible for retaining all material obtained in a criminal investigation that may be relevant to the investigation

Question 14

What is material ‘relevant to an investigation’?

Answer 14

Material that appears to an investigator or disclosure officer in that it has merely some bearing on any offence under investigation or any person being investigated, or on the surrounding circumstances of the case.

Question 15

What is ‘material’?

Answer 15

Material gathered in the course of the investigation and generated by the investigation.

Material will include, for example, the following categories of material:
* crime reports, including crime report forms.
* relevant parts of incident report books and police officers’ notebooks.
* final versions of witness statements.
* draft versions of witness statements where their content differs from the final version.
* interview records (written or taped).
* expert reports and schedules.
* any material casting doubt upon the reliability of a confession;
* and any material casting doubt on the reliability of a witness.

The CPIA Code makes clear that the duty to retain material does not extend to items purely ancillary to the above categories which possess no independent significance, such as duplicates of documents

Question 16

What must a disclosure officer do in respect of unused?

Answer 16

List on them on a schedule.

Question 17

In what cases must an officer form a schedule of unused?

Answer 17

The obligation to prepare a schedule arises in all cases that will be heard, or are likely to be heard, in the Crown Court and all cases in the magistrates’ court where the accused is likely to plead not guilty.

Question 18

What form should the disclosure officer prepare the schedule of unused on?

Answer 18

In the Crown Court, an MG6C.

In the Mags, a streamlined disclosure certificate.

Question 19

What does the prosecutor do in respect of the MG6C/disclosure certificate?

Answer 19

Review it to see whether any material should be disclosed to the defence, applying the relevant statutory test.

He also gives a copy to the defence (redacted if necessary)

Question 20

What material is likely to be relevant for prosecution disclosure?

Answer 20

• records of telephone messages
• incident logs
• contemporaneous records of the incident (such as crime reports and crime report forms, police notebook entries, records of actions carried out by officers and CCTV footage)
• custody records
• previous accounts of complainants or witnesses
• interview records (written or taped)
• and any material casting doubt on the reliability of a witness.

Question 21

What should be done in respect of ‘sensitive material’?

Answer 21

Any ‘sensitive material’ should be listed in a separate schedule or, exceptionally, disclosed to the prosecutor separately.

Question 22

What counts as ‘sensitive material’?

Answer 22

Material which the investigator believes would give rise to a real risk of serious prejudice to an important public interest if it were to be disclosed.

Examples of such material include:
* material relating to national security to material given in confidence
* material relating to informants
* undercover police officers
* premises used for police surveillance
* techniques used in the detection of crime
* and material relating to child witnesses

Question 23

What are the guidelines on non-sensitive schedules of unused?

Answer 23

Descriptions by disclosure officers in non-sensitive schedules should be clear and accurate and must contain sufficient detail to enable the prosecutor to make an informed decision on disclosure.

Question 24

What are the guidelines on sensitive schedules of unused?

Answer 24

Sensitive schedules must contain sufficient information to enable the prosecutor to decide whether the material should be viewed, bearing in mind its confidential nature

Question 25

What must the investigator draw the prosecutor's attention to?

Answer 25

Any material which might satisfy the test for prosecution disclosure and must give the prosecutor a copy of any material falling within certain categories in the CPIA Code, para 7.4, which includes: * information provided by an accused person which indicates an explanation for the offence with which he has been charged; * any material casting doubt on the reliability of a confession; * any material casting doubt on the reliability of a prosecution witness; * any other material which the investigator believes may satisfy the test for prosecution disclosure in the Act.

Question 26

What must the disclosure officer do at the end of the unused disclosure process?

Answer 26

A disclosure officer must certify to the prosecutor that to the best of the officer's knowledge and belief the duties imposed under the Code have been complied with.

Question 27

What duty is the prosecutor under re unused evidence?

Answer 27

To assess the need to make disclosure of the material to the defence in accordance with the statutory test for disclosure. Furthermore, the prosecutor's disclosure obligations are a continuing duty, and disclosure should be kept under review throughout proceedings.

Question 28

What do the guidelines say on prosecutor's duties on unused disclosure?

Answer 28

The A-G's Guidelines require prosecutors to do all that they can to facilitate proper disclosure. This includes: * bringing concerns about inadequate inspection of relevant material to the attention of disclosure officers * probing actions taken by investigators * reviewing schedules (taking action to ensure they are complete and adequate where necessary) * and considering defence statements thoroughly. Where defence statements are inadequate, prosecutors should challenge this in writing. * Prosecutors should provide the investigator with a copy of the defence statement and advise the disclosure officer on whether any further reasonable lines of inquiry need to be pursued, what to look for when reviewing unused material and what further material may need to be disclosed. In summary, prosecution advocates must ensure that all material which ought to be disclosed is disclosed to the defence, satisfy themselves that they are in possession of all relevant material and that they have been fully instructed as regards disclosure matters, and keep all disclosure decisions under review.

Question 29

What do the authorities say regarding unused disclosure in long and complex fraud cases w/ large volumes of material?

Answer 29

(a) The prosecution must be in the driving seat at the stage of primary disclosure. (b) The prosecution must encourage dialogue and prompt engagement with the defence. (c) The law is prescriptive of the result of disclosure, not the method by which the process should operate. (d) The process should be subject to robust case management by the judge, utilising the full range of case management powers. (e) Flexibility is critical. The practice of 'dip sampling' material and the use of search tools by the prosecution to satisfy the disclosure obligation in a practicable and effective manner where the quantity of material to be reviewed would be unmanageable otherwise has been endorsed.

Question 30

What is the pre-charge engagement scheme?

Answer 30

A scheme under which prosecutors, investigators, suspects and suspects' legal representatives may enter into discussions about an investigation at any time after the first PACE interview and before charge.

Question 31

Could failing to use the pre-charge engagement scheme be held against the defendant?

Answer 31

The pre-charge engagement scheme is voluntary and may be terminated at any time. A decision not to engage should not be held against the defendant. No adverse inferences can be drawn when asked in pre-charge engagement.

Question 32

Where is the pre-charge engagement scheme not applicable?

Answer 32

* to discussions regarding pleas to an allegation of serious or complex fraud * to formal agreements relating to the provision of information or evidence about the criminal activities of others * engagement between the parties to an investigation by way of further PACE interviews * should not be considered a replacement to a further interview with a suspect * and should not be sought in respect of matters where it is likely that the prosecution will seek to rely on the contents of the suspect's answers as evidence at trial.

Question 33

What could pre-charge engagement consist of?

Answer 33

(a) giving the suspect the opportunity to comment on any proposed further lines of inquiry and to identify new ones (although only lines of inquiry reasonable in the circumstance of the case should be followed); (b) asking whether the suspect is aware of, or can provide access to, relevant digital material; (c) agreeing key word searches of digital material with the suspect; (d) obtaining a suspect's consent to access medical records; (e) the suspect identifying potential witnesses; and (f) clarifying whether expert or forensic evidence is agreed.

Question 34

When can the pre-charge engagement process be started?

Answer 34

Whenever it is agreed between the parties that it may assist the investigation. Care should be taken to ensure that unrepresented suspects understand their right to legal advice and are given an opportunity to obtain representation before the pre-charge engagement process commences.

Question 35

Who may pre-charge engagement be initiated by?

Answer 35

The pre-charge engagement process may be initiated and conducted by investigators, prosecutors, suspects' representatives or unrepresented suspects depending on what is appropriate and practical in the circumstances. Prosecutors and investigators should be alert to the use of pre-charge engagement as a means to frustrate or delay the investigation unnecessarily. Engagement should not be initiated or continued where this is apparent.

Question 36

Does the statutory disclosure regime apply to the pre-charge engagement scheme?

Answer 36

No, but disclosure of unused material must be considered as part of the pre-charge engagement process, to ensure that the discussions are fair and that the suspect is not misled as to the strength of the prosecution case

Question 37

What should be recorded in the pre-charge disclosure scheme?

Answer 37

Recording of all key actions involved in the pre-charge engagement process and all information provided to and from the suspect's representative. Pre-charge engagement discussions should be recorded in full and the record signed.

Question 38

What should be disclosed post-charge but prior to statutory obligation?

Answer 38

The CPIA Code requires disclosure with the initial details of the case of material that might assist the defence with the early preparation of its case or at a bail hearing, irrespective of the anticipated plea. Examples of such material cited in the Code are relevant previous convictions of key prosecution witnesses and statements that have been withdrawn by witnesses. Furthermore, the following material might be relevant to disclose early: (a) the previous convictions of the alleged victim when they might be expected to help the defence in a bail application; (b) material to help an application to stay proceedings as an abuse of process; (c) material to help the accused prepare for trial, e.g., eye-witnesses whom the prosecution did not intend to use. A responsible prosecutor should consider whether fairness required that some of this material might be disclosed. The question was: what immediate disclosure (if any) did justice and fairness require in the circumstances of the case? The Court found that the extent of the disclosure required at this stage was not the 'full blown' extent required under the CPIA 1996.

Question 39

Where is the test for disclosure?

Answer 39

S3 CPIA 1996.

Question 40

What is the statutory test for disclosure?

Answer 40

Material which might reasonably be considered capable of undermining the case for the prosecution against the accused, or of assisting the case for the accused.

Question 41

What must occur if there is no disclosable material?

Answer 41

The accused must be given a written statement to that effect. The court officer must be informed by the prosecutor at the same time

Question 42

What is 'prosecution material'?

Answer 42

Prosecution material is defined as material which the prosecutor possesses or has been allowed to inspect under the provisions of the CPIA Code in connection with the case against the accused.

Question 43

Does the test require disclosure of material which is neutral or adverse to the accused?

Answer 43

No.

Question 44

Should prosecution advocates disclose as much as possible, even where it does not meet the disclosure test?

Answer 44

No, as the trial process might be diverted or overburdened.

Question 45

What factors should the prosecution consider when applying the s.3 test for initial disclosure?

Answer 45

(a) the use that might be made of the material in cross-examination; (b) its capacity to support submissions that could lead to the exclusion of evidence, a stay of proceedings or a finding that any public authority had acted incompatibly with the accused's rights under the ECHR; (c) its capacity to suggest an explanation or partial explanation of the accused's actions; (d) its capacity to undermine the reliability or credibility of a prosecution witness; (e) the capacity of the material to have a bearing on scientific or medical evidence in the case.

Question 46

What material is likely to fall to be disclosed?

Answer 46

Material relating to the accused's mental or physical health, intellectual capacity, or to any ill-treatment which the accused may have suffered in custody. Material known to the disclosure officer that might assist the defence with the early preparation of their case or at a bail hearing * Records which are derived from tapes or recordings of telephone messages (for example, 999 calls) containing descriptions of an alleged offence or offender; * Any incident logs relating to the allegation; * Contemporaneous records of the incident, such as: * crime reports and crime report forms; * an investigation log; * any record or note made by an investigator (including police notebook entries and other handwritten notes) on which they later make a statement or which relates to contact with suspects, victims or witnesses; * an account of an incident or information relevant to an incident noted by an investigator in manuscript or electronically; * records of actions carried out by officers (such as house-to-house interviews, CCTV or forensic enquiries) noted by a police officer in manuscript or electronically; * CCTV footage, or other imagery, of the incident in action;

Question 47

What are disclosure management documents and what is their role?

Answer 47

Disclosure Management Documents outlining the strategy and approach to disclosure are now required in all Crown Court cases, and these should be served to the defence and the court as early as possible and in any event no less than seven days before the PTPH. The content of Disclosure Management Documents may include, for example: an explanation as to how disclosure responsibilities have been managed, a summary of the prosecution case, a statement outlining how the prosecutor's approach will comply with the CPIA 1996 regime, and the prosecutor's understanding of the defence case. Detail relating to the following may also be set out: lines of inquiry pursued, timescales for disclosure, the method and extent of examination of digital material, any potential video footage, steps taken to obtain any third party or international material and the credibility of prosecution witnesses.

Question 48

What should happen re disclosure in cases with large amounts of digital material?

Answer 48

Investigators should complete an Investigation Management Document which will inform the Disclosure Management Document that prosecutors should complete. Ideally, the investigator should consult the prosecutor before the digital material is seized, and in turn they may consider seeking advice from a digital forensic specialist on the strategy for the identification and review of digital material. The defence must also play their part in identifying the real issues in the case, including by defining the scope of any reasonable searches that may locate digital material that meets the disclosure test

Question 49

How should documents be disclosed?

Answer 49

A prosecutor may disclose material to the defence either by providing a copy of the material or allowing inspection at a reasonable time and place. Where a prosecutor has been given a schedule of unused material and decides its disclosable, that schedule must be served on the accused.

Question 50

When must material not be disclosed?

Answer 50

If a court has concluded that it is not in the public interest that it be disclosed, if its disclosure is prohibited by the IPA 2016, s. 56.

Question 51

When should disclosure management documents be used in the magistrates' court?

Answer 51

In cases heard in the magistrates' court and the youth court, prosecutors should always consider whether a Disclosure Management Document would be beneficial. They are most likely to be beneficial in cases involving: substantial or complex third party material digital material in which parameters of search, examination or analysis have been set international inquiries linked operations non-recent offending and material held or sought by the investigation that is susceptible to a claim of legal professional privilege

Question 52

What are the time limits on disclosure?

Answer 52

No statutory time limits, however in the Crown the position is that disclosure must be made as soon as reasonably practicable. In the Magistrates' Court, the streamlined disclosure certificate must be disclosed either at the hearing where a not guilty plea will be entered or as soon as possible following the formal indication that a not guilty plea will be entered.

Question 53

What should the judge do regarding disclosure at a preliminary hearing?

Answer 53

If there is a preliminary hearing, the judge should seize the opportunity to impose an early timetable for disclosure and any likely problems regarding third party material.

Question 54

What is the continuing duty of disclosure?

Answer 54

The prosecutor is under a continuing duty of disclosure, where a prosecutor must disclose at any time before an accused is acquitted or found guilty.

Question 55

What must happen after the service of the defence case statement?

Answer 55

After service of the defence case statement, a repeat of the process for initial disclosure should be conducted.

Question 56

Is the investigator under any continuing disclosure duties?

Answer 56

Yes, if the investigator comes into possession of anything which may require disclosure to the prosecutor they should do so.

Question 57

What may occur if a prosecution witness gives materially inconsistent evidence as to their previous statement?

Answer 57

If a prosecution witness gives evidence materially inconsistent with a statement made earlier to the police, the duty to disclose that previous statement may be triggered.

Question 58

What disclosure duties are there post-conviction?

Answer 58

Post-conviction, there is no general duty on the state to continue to investigate as the duties terminate with conviction, acquittal, or discontinuation. However, there is a duty on the state between conviction and sentence to disclose evidence which is relevant to sentence. Furthermore, in Onuigbo (also known as Okoronkwo) [2014] EWCA Crim 65, the Court of Appeal approved a statement that the common law, A-G's Guidelines and the ECHR, Article 6, obliged a prosecutor to continue to review unused material, particularly following the receipt of any response to a confiscation statement. Once proceedings have concluded, the prosecution are still under a duty to disclose any material which might reasonably be considered capable of casting doubt on the safety of the conviction.

Question 59

When may an accused apply for further prosecution disclosure?

Answer 59

Once the defence statement has been disclosed and the prosecution have complied, purported to comply, or failed to comply with further disclosure, the accused may apply under s8 CPIA for disclosure of material under 7A. This can only be made if an adequate defence statement has been made.

Question 60

What is the procedure for applying for more disclosure?

Answer 60

The procedure for applying for further disclosure is: An application must describe the material which is subject to the application and explain why there is reasonable cause to believe that the prosecutor is in possession of the material and why it meets the test for disclosure. Prosecutors must review this application and consider it too. This can be made by written submissions by a limited length.

Question 61

When must an accused give a defence statement?

Answer 61

After the case is sent to the crown and prosecution case is served, the accused must give a defence statement.

Question 62

What does a defence statement consist of?

Answer 62

A defence statement is written and must cover (6A CPIA 1996): * the nature of the accused’s defence, including any particular defences the accused will rely upon * the matters of fact the accused will take issue with, the reasons why * the matters of fact the accused will intend to rely upon * any points of law the accused will take, and authorities relied upon

Question 63

What would make for an inadequate defence statement?

Answer 63

A general denial is an inadequate defence statement, though it is perfectly possible for the accused to ask the prosecution to prove it. Defence statements should not be general or unspecified, or describe the defence ambiguously. In appropriate circumstances the principle that there must be equality of arms will mean that the prosecution must spell out the inferences that they will be asking the trier of fact to draw from the facts adduced in their evidence, given that the defence are obliged to set out their reasoning for disputing issues of fact in that evidence. It follows that the scope of the defence statement should be viewed in the context of what might reasonably be required of the defence at a stage when they may not be clear about the way in which the prosecution put their case.

Question 64

What should happen with alibis in defence statements?

Answer 64

If an aibli is disclosed, the particulars must be given. This includes: * names * address * dates of birth if known of any alibi witnesses the accused intendeds to call. If not known, the accused must give any information that would help identifying or finding any such witness. Alibi evidence is ‘evidence tending to show that by reason of the presence of the accused at a particular place or area at a particular time he was not, or unlikely to have been, at the place where the offence is alleged to have been committed at the time of its alleged commission’. The obligation to give this information is triggered by the accused's belief that the witness has that information, not whether they can or will.

Question 65

What must a defendant do re disclosure of witnesses?

Answer 65

The defence must notify the prosecution and court (separately of the defence statement) of any witnesses they intend to call at trial, other than the defendant and any alibi witnesses already identified. The following must be provided: * Names * Addresses * Dates of birth * Any other identifying information Notice must be given within 14 days (summary) or 28 days (crown) from the date the prosecutor purports to comply with the duty to disclose. There is provision for an extension, for treatment of weekends and bank hbolidays. Any change to call witnesses must be dealt with by way of amended notice. Overrides litigation and legal professional privilege.

Question 66

What is the position on defence disclosure in the mags?

Answer 66

In summary cases, there is no obligation on a defence statement – it is discretionary. However, without a defence statement, no application for specific disclosure under s8 can be made, and the court cannot make any orders for disclosure of unused. Where an accused chooses to serve a defence statement, this must be done within 14 days of receipt of initial disclosure. The court can extend this time limit on application of accused. If the accused chooses to provide the statement, the requirements of 6A apply. This regime applies even for indictable offences where they are a child or young person. The defence must identify the real issues even where no defence statement is served.

Question 67

When can an extension of time be given for a defence statement?

Answer 67

An extension can be given only where an application is made before time expires. The application must not be granted unless the court is satisfied that it would not be reasonable to require the accused to give a defence statement within 28 days. Any application should be accompanied with appropriate explanations. There is no limit to the number of applications to be made.

Question 68

When does time start running for the time to give a defence statement?

Answer 68

Time runs from the date of service of a statement by the prosecution, not from service of the unused material.

Question 69

Is the right to further disclosure lost if there is a short delay in serving the defence statement?

Answer 69

No

Question 70

When may sanctions apply for failures in defence statement?

Answer 70

S11 CPIA: (a) fails to give the initial defence statement required under s. 5 in respect of Crown Court cases; (b) gives the initial defence statement after the 14-day period during which it must be served in the magistrates' court or after the 28-day period during which it must be served in the Crown Court (see D9.41); (c) fails to provide an updated statement required under s. 6B(1) or a statement that no updating is necessary under s. 6B(4) (note, however, that s. 6B is not yet in force); d) supplies the documents in (c) outside the applicable time-limit; (e) sets out inconsistent defences in the defence statement; (f) puts forward a defence at trial that was not mentioned in the defence statement; (g) relies on a matter that should have been mentioned in the defence statement to comply with s. 6A, but was not; (h) gives evidence of alibi or call a witness to give evidence in support of alibi without having complied with the provisions relating to notification of alibi witnesses; (i) calls a witness not included or adequately identified in the notice of defence witnesses.

Question 71

What are the consequences of a defence disclosure failing?

Answer 71

In the event there is a defence failing, the court may comment, other parties may comment (but only with leave of the court where it is a failure to mention a point of law or authority, failure to give notice or adequately identify a witness, or failure to give notice in time). If any deficiencies apply, the court or jury may also draw such inferences as appear proper (but not convict solely on the basis of inference). This also cannot be applied to a prosecution case against a submission of no case to answer. The only sanctions available are in s 11.

Question 72

Are there any occasions where material which tends to undermine or assist the defence case can be withheld?

Answer 72

There are occasions where material held by the prosecution and tending to undermine or assist cannot be disclosed without the risk of prejudice to an important public interest. In such circumstances, a court may be justified in withholding that material, but only to the minimum extent necessary to protect the public interest and must never imperil the overall fairness of the trial. Applications to withhold this material are called Public interest Immunity apps.

Question 73

How should potential PII material be handled?

Answer 73

Material which may be subject to a PII app must be recorded in a sensitive schedule. Investigators should specify reasons why the material is sensitive, the degree of sensitivity, the consequences of revealing it, the significance of the material, the involvement of third parties in bringing the material to the attention of the police, the implications for continuance of prosecution if the disclosure is ordered, and whether it is possible to disclose without affecting public interest. Prosecutors are to consider possibility or prejudice to the public interest through direct harm or indirectly through incremental or cumulative harm.

Question 74

How should third party disclosure be handled?

Answer 74

Where an investigation reveals the existence of material held by a third party but such material is not obtained, the third party must be informed of the investigation and invited to hold the material in case a request for disclosure has been made. Whilst speculative inquires are not required, there must be some reason to believe they hold the relevant material, the test of what are reasonable investigative steps in the circumstances is to start from the position of a persistent prosecutor who does not readily take no for an answer. The margin of discretion attributable to a prosecutor in pursuing third party material is confined by considerations of fairness at common law and under the ECHR.

Question 75

What lines of inquiry should the prosecution pursue?

Answer 75

The CPIA code of practice and the Ag’s guidelines require pursuit of all reasonable lines of inquiry, whether towards or away from the suspect. This does not require an endless investigation, so thought must be given to defining the scope of the investigation. The obligation to make disclosure cannot be avoided by declining to make an inquiry which might produce disclosable material, but prosecutors are not required to investigate or obtain evidence which would help the defence.