Jessica Rooks, R (on the application of) v Crown Prosecution Service

Judicial review of a prosecutorial decision is available only on conventional public-law grounds, including unlawful policy, failure to follow lawful policy, irrationality, or an error of law. The court must respect the CPS’s constitutional independence, expertise and substantial margin of judgment, particularly when the issue concerns disputed primary facts, credibility and the likely response of a jury.

A continuing review process must be assessed as a whole. A later decision-maker need not repeat every point considered in earlier reviews, provided the relevant law and material have been adequately addressed. The court should read a decision letter broadly and sensibly. It must not substitute its assessment of the evidence for that of the prosecutor.

The claimant sought judicial review of the CPS decision to offer no evidence against her former partner on a charge of assault occasioning actual bodily harm. The prosecution had initially passed the evidential stage of the Full Code Test but was discontinued after further material arose concerning the claimant’s credibility, including evidence obtained following her arrest.

The claimant argued that the final review unlawfully failed to consider the objective limb of self-defence, namely whether the force used was proportionate to the perceived threat. The CPS maintained that the reviews, considered cumulatively, addressed the legal issues and lawfully reassessed the strength of the evidence. The central issue was whether the decision contained an error of law or another justiciable public-law failing.

1. The claim was dismissed. The decision of 1 February 2022 was not unlawful and contained no error of law or other justiciable failing.
2. The court’s power to review prosecutorial decisions is narrowly confined. It may intervene where the policy is unlawful, lawful policy has not been followed, or the decision is irrational, including where the decision-maker has applied the law incorrectly. The CPS’s expertise and constitutional role require a substantial margin of judgment, especially on disputed primary facts, credibility and the likely reaction of a tribunal of fact: [1995] 1 Cr App R 136; [2013] EWHC 1752 (Admin); [2022] EWHC 3508 (Admin); [2019] EWHC 9 (Admin).
3. The Full Code Test required an objective assessment of whether the evidence, including the defence and other material on which the suspect might rely, gave rise to a realistic prospect of conviction. The first and second reviews had considered both parts of self-defence, including whether the force used was proportionate to the perceived threat.
4. The review process was continuing. The final decision did not need to recite every point addressed in earlier reviews. The earlier assessment of the injuries and proportionality of the force remained part of the reasoning process, even though it was not repeated in the final letter. The decision had to be assessed by its substance rather than imperfections in its expression.
5. The CPS was entitled to conclude that the later evidence substantially damaged the claimant’s credibility and reduced the prospect of conviction below the evidential threshold. The court could not re-evaluate that evidence or substitute its own view. The decision was reached after consideration of relevant material and without reliance on an unlawful or irrelevant consideration.