It was the prosecution's case, therefore, that the appellant had conspired with Ryan Parry to persuade Liam and Barry Roberts either to alter their evidence or to avoid testifying altogether... Finally, the Crown, with the leave of the judge, introduced (only towards the end of the trial) evidence of Ryan Parry's guilty to plea to conspiracy to pervert the course of public justice as some support for the truthfulness of Liam and Barry Roberts. This was admitted pursuant to section 74 (1) Police and Criminal Evidence Act 1984:
In essence, it is submitted by the appellant that the judge erred in admitting the evidence of Ryan Parry's guilty plea, given this was alleged to have been a "closed conspiracy" consisting solely of the appellant and Ryan Parry. In those circumstances it is submitted that it was inevitable that the jury would have concluded, however the judge directed them, that Parry's plea demonstrated the appellant's guilt.
We have no doubt that the introduction of Ryan Parry's plea would have tended significantly to close down the central issue relevant to this count, namely whether the appellant entered into this conspiracy with Ryan Parry, which was the charge he faced. The latter could not have been guilty of this offence unless the appellant was also guilty, and, considered with a degree of realism, Parry's involvement entirely depended on the participation – indeed, the direction – of the appellant. There would have been no sense in Parry taking these steps unless the appellant considered them necessary in order to enable him to present a false defence. Furthermore, once the conviction was admitted into evidence, it was not admitted as a mere plea of guilty but instead it included all the detail in the count. Notwithstanding the judge's directions in which he sought to limit the evidential impact of this evidence, there was a high risk that the jury would have drawn the conclusion that Ryan Parry's admission that he had conspired with the appellant meant inevitably that the appellant had conspired with him. Given the fact on which the conviction was based was that Ryan Parry and the appellant conspired together—and it takes at least two conspirators to make a conspiracy—then the conviction proved just that: Ryan Parry and the appellant were both guilty of conspiracy.