Criminal Procedure Act 1986 (NSW), s 21(2)
The Crown is entitled to join more than one accused in a single indictment. However, an accused can make an application for a separate trial where he or she may be prejudiced or embarrassed in his or her defence by a joint trial or the court is of the opinion that for any other reason the accused should be tried separately: s 21(2) Criminal Procedure Act 1986.
As to the public policy considerations favouring joint trials, see Webb v The Queen (1994) 181 CLR 41 per Toohey J. For the principles to be applied in deciding to grant a separate trial, see Ross v R  NSWCCA 207 at .
See generally Criminal Practice and Procedure NSW at [2-s 21.15] and Criminal Law (NSW) at [CPA.21.20]ff.
Where the evidence at the trial is admissible against each accused, it is not necessary for the judge to address the case against each separately: Huynh v The Queen  HCA 6 at .
It is convenient to approach the admissibility of evidence on the basis that the jury should assume that the evidence is admissible against all of the accused unless told otherwise. See relevant sections of Suggested direction — advice/instructions to the jury on empanelling at [1-520]. The Crown should be required to indicate to the jury, when calling a particular piece of evidence or a particular witness, if it is not tendered against all the accused and the limited basis upon which it is being tendered. The trial judge should direct the jury as to the limited use to be made of evidence tendered against an individual accused, see R v Masters (1992) 26 NSWLR 450 at 455. This is particularly so where the evidence is of an admission implicating a co-accused.
It is suggested that directions as to the admissibility of evidence against a particular accused and the limited use that can be made of the evidence be given at the time the particular evidence is led before the jury. Later the summing up should make it clear what is the particular case against each of the accused and direct the jury against using evidence admitted against one accused as evidence against another accused.
[3-360] Suggested direction — joint trial
As you are well aware by now this is a joint trial of [number] accused. I told you at the outset of the trial that this was simply a matter of administrative convenience. But I also told you that you have to consider the case against each accused person separately when considering your verdicts. You will be required to return a separate verdict in respect of each individual accused. You should not, in your deliberations, try to determine whether [both/all] of the accused are guilty without considering them as individuals and giving each separate consideration. Simply because the Crown allegation is that they are [each/all] guilty of the same offence, it does not follow that you approach your deliberations in the same way.
There is nothing in law, or for that matter in common sense, which requires you to return the same verdict in respect of each individual accused.]
You should understand by now that the evidence relied upon by the Crown to prove the guilt of each accused differs. You must not during the course of your deliberations take into account in deciding whether the Crown has proved its case against one accused, use evidence that was tendered only against the [other/another] accused. It would be a breach of your duty to decide the case according to law, as well as grossly unfair, to use evidence against an accused which the Crown did not rely upon in proof of its case against [him/her].
Detail how the case against the individual accused differs by indicating what evidence is, or is not, admissible against a particular accused.]