3.1 A prosecutor is required to comply with and promote the rule of law. A prosecutor acts on behalf of the community in an impartial manner and as a “minister of justice”. To this end, a prosecutor must fairly and objectively assist the court to arrive at the truth and to do justice between the community and the accused according to law.
3.2 In the Supreme Court of Canada, Rand J. stated in Boucher v The Queen  SCR 16 at 23-24:
“It cannot be over-emphasized that the purpose of a criminal prosecution is not to obtain a conviction, it is to lay before a jury what the Crown considers to be credible evidence relevant to what is alleged to be a crime. Counsel have a duty to see that all available legal proof of the facts is presented: it should be done firmly and pressed to its legitimate strength, but it must also be done fairly. The role of prosecutor excludes any notion of winning or losing; his function is a matter of public duty than which in civil life there can be none charged with greater personal responsibility. It is to be efficiently performed with an ingrained sense of the dignity, the seriousness and the justness of judicial proceedings.”
3.3 A prosecutor works in an adversarial and accusatorial litigation system. The prosecutor’s advocacy role must be conducted temperately and with restraint; nevertheless, a prosecutor is entitled to advocate firmly and courteously the prosecution’s position on an issue and to test and, if necessary, attack the position adopted or evidence advanced on behalf of an accused.
3.4 Prosecutors carry out their roles as an integral part of a criminal justice process that includes investigation, prosecution, defence, adjudication and punishment. Their contribution to the criminal justice process and the outcomes achieved must be made professionally and to the highest standards reasonably achievable. Prosecutors should not seek to step beyond the proper roles of the prosecution in the criminal justice process.
3.5 In litigation, a prosecutor must fairly:
3.6 A prosecutor must not argue any proposition of fact or law which the prosecutor does not believe on reasonable grounds to carry weight and to be capable of reasonably contributing to a decision of the court. Material put to a witness (including an accused) must be considered on reasonable grounds to be accurate and reliable and its use justified in the circumstances.
3.7 A prosecutor must not lead the court or defence to believe that the prosecution has evidence supporting an aspect of its case unless the prosecutor believes on reasonable grounds that such evidence will be produced from material already available to the prosecutor.
3.8 A prosecutor must at all times assist the court to avoid appealable error and must strive to correct any error of law or fact that becomes apparent in the course of the trial and sentence proceedings.
3.9 A prosecutor should prepare and assemble all relevant evidence available to the prosecution well in advance of trial. The prosecution should, as a general rule, offer all its evidence during the presentation of its case. It should inform the court and defence of authorities, warnings and directions that may be appropriate, even if unfavourable to the prosecution case.
3.10 The prosecution must identify any relevant material available to him or her that may not be admissible evidence (including on the ground that it appears to have been obtained illegally or improperly). The prosecution may decline to adduce such material and, as part of its disclosure obligations, inform the defence of such unused material. If the prosecution decides to lead such material as evidence, it must inform the defence. If the defence objects to its admission, the admissibility of such evidence may be determined by the court.
3.11 A prosecutor also owes a duty of fairness to the community, through carrying out the responsibilities of prosecuting in as effective and efficient a fashion as is reasonably possible.
3.12 A prosecutor, in carrying out his or her role, is in a position to affect substantially the human rights of suspects, accused, victims, witnesses and other members of the public. A prosecutor has an obligation to be aware of those rights, as well as their sources, and to respect or give effect to them as appropriate in the course of criminal proceedings.
3.13 The Basic Law (“BL”)and the Hong Kong Bill of Rights Ordinance (“BOR”), Cap. 383 provide the fundamental rights of Hong Kong residents and others, many of which may arise for consideration in the conduct of criminal proceedings. Prosecutors must understand the impact of these instruments on their work and adhere to their requirements at all times.
3.14 BL Article 8 preserves the laws previously in force, including the common law. BL Article 39 provides that the provisions of the International Covenant on Civil and Political Rights (“ICCPR”) as applied to Hong Kong shall remain in force and shall be implemented through the laws of Hong Kong. The BOR is the main instrument for implementing the ICCPR as applied to Hong Kong.
3.15 The prosecutor must be alert to the rights of an accused which are relevant to the prosecution process, including equality before the law, the rights to have confidential legal advice, to be presumed innocent, and to have a fair trial without undue delay under BL Articles 25, 35 and 87 (BOR Articles 10 and 11).
3.16 In determining whether to prosecute a case or to continue a prosecution, account should be taken of the rights of an accused, and other parties to the proceedings. The prosecutor should be aware that the Basic Law recognizes freedom of speech (Article 27; BOR Article 16(2)); inviolability of the freedom of the person (Article 28; BOR Article 5); inviolability of the home (Article 29; BOR Article 14); freedom and privacy of communication (Article 30; BOR Article 14); freedom of movement (Article 31; BOR Article 8); freedom of conscience and religion (Article 32; BOR Article 15).