O'Brien, R (on the application of) v Director of Public Prosecution

A prosecutorial decision not to charge may be reviewed only on limited public-law grounds, including unlawfulness, failure to follow settled policy, or perversity. In the present context, the question was whether it was unreasonable for the prosecutor to conclude that a properly directed jury would have no realistic prospect of being sure of guilt. A court should exercise particular restraint when reviewing an independent prosecutor’s assessment of evidence. Even where aspects of the reasoning disclose a public-law error, quashing will rarely be appropriate if there is no real likelihood of a successful prosecution. Expert evidence concerning pauses in an anxious conversation was of doubtful admissibility and, in any event, weak. The prosecutor’s decision was reasonable and correct.

Michael O’Brien sought judicial review of the Crown Prosecution Service decision not to prosecute former detective Stuart Lewis for offences arising from an alleged incriminating conversation overheard in police cells in 1987. Mr O’Brien alleged that the conversation had been fabricated. The prosecutor assessed witness evidence, custody records, expert evidence concerning the recording of speech, and the prospects of a realistic conviction.

The challenge alleged misdirection, an unbalanced assessment of the evidence, and failure to consider relevant matters. The central issue was whether the prosecutor’s conclusion that a properly directed jury could not be sure of guilt was unreasonable or perverse.

1. Applicable standard. The court applied the approach in R v Director of Public Prosecutions ex parte C [1995] 1 CAR 136. Intervention is justified only for an unlawful policy, failure to follow the prosecutor’s settled policy, or perversity. In this case the issue was whether it was unreasonable to conclude that there was no realistic prospect that a properly directed jury would be sure of guilt.
2. Prosecutorial restraint. Judicial review is discretionary. Given prosecutorial independence and the CPS victim’s Right to Review Scheme, it would only rarely be appropriate to quash a decision where the court considered that a successful prosecution was unlikely, even if there were detailed criticisms capable of amounting to public-law errors. The court referred to L v DPP [2013] EWHL 1752 (Admin) regarding the scheme.
3. Assessment of the evidence. The prosecutor overstated the likelihood that a trial would become a retrial of the original murder. That was an error, although the relevant credibility evidence remained admissible and distinct from the issue of guilt. The error did not undermine the overall decision.
4. Expert evidence. The prosecutor slightly overstated Professor Coulthard’s view of the performance of an experienced detective. That was a detail. The court also held that whether two anxious suspects paused during a conversation was doubtfully a proper subject for expert evidence. Even if admitted, evidence against pauses was weak. The remaining evidence did not provide a realistic prospect of conviction.
5. The application for judicial review was dismissed. The prosecutor’s decision was reasonable and correct.

First-instance judicial review proceedings. The judgment states that the Court of Appeal (Criminal Division) had previously quashed the claimant’s murder conviction, but this was part of the factual background and not an appellate stage of the present claim.