Where there's a will there's --always-- been a way in this case. You can't have a prosecuting witness in the stand who's committed fraud.
Its here Lookout, the jury knew about the Cheque book fraud.
The jury knew about the admissions made to the police. They further knew that neither of the girls had been prosecuted for these offences. Julie Mugford told the jury that she had "got a caution for it". When the judge summed the case up to the jury, he referred to her receiving "a police caution". Mr Turner's submission is that the jury were misled by being told that she had received a "police caution", and that the prosecution were under a duty to correct this wrong impression.
334. It is undoubtedly correct that Julie Mugford had not received a formal police caution in the sense that that expression is clearly understood by police officers and lawyers. It may be that the trial judge in translating Miss Mugford's reference to a caution into a formal police caution had misunderstood the position. However it seems unlikely to us that the jury would have understood the significance of a formal police caution as opposed to any other warning as to her future behaviour.
335. However, whether or not the jury understood the legal distinction of a formal police caution, we fail to see how this could have had any possible impact upon their considerations. What mattered in assessing the weight to be given to the witness's evidence was their own admitted dishonesty, and how they had behaved in relation to such dishonesty, not how the authorities had responded to their admissions. Any failure to correct the judge's reference to a formal police caution cannot be laid at the door of the police since the position was clearly understood by the lawyers and hence such a failure could not in any way taint the evidence of the police officers involved in the inquiry.
Sometimes it works in favour of the accused, he can have a past that the Jury don’t get to hear about, he could be a sex offender and the Jury wouldn't always get to hear about it?