Fresh CPTSD Evidence and Loss of Control: When New Psychiatric Labels Cannot Recast a Trial Strategy on Appeal

3.1 Precedents Cited

R v Rejmanski [2017] EWCA Crim 2061

The Court relied on R v Rejmanski [2017] EWCA Crim 2061 as authority that mental health conditions of this kind are irrelevant and inadmissible to the “normal person” limb in section 54(1)(c) and section 54(3) (i.e. circumstances whose only relevance is to general capacity for tolerance/self-restraint).

Importantly, Rejmanski also supports the limited counterpoint adopted here: such evidence may sometimes be relevant to the gravity of the qualifying trigger—not by lowering the standard of self-restraint, but by illuminating how the trigger may reasonably be experienced as more grave.

R v Sargeant [2019] EWCA Crim 1088

R v Sargeant [2019] EWCA Crim 1088 was cited to illustrate that the Court has accepted, consistently with Rejmanski, that psychiatric material may assist on the gravity of a trigger. The present Court additionally used Sargeant to emphasise the practical point that self-defence and loss of control rarely sit comfortably together; where both are in play, the evidential foundation and forensic coherence are critical.

R v Cross [2014] EWCA Crim 96

The Court used R v Cross [2014] EWCA Crim 96 for procedure: where a ground depends entirely on proposed fresh evidence, a “rolled-up” hearing may be ordered (considering admission of evidence, leave, and, if granted, the appeal). This case followed that model, including consideration of the materials de bene esse.

R v Erskine (Kenneth) [2009] EWCA Crim 1425; [2009] 2 Cr App R 29

The Court treated R v Erskine (Kenneth) [2009] EWCA Crim 1425; [2009] 2 Cr App R 29 as the key safeguard against re-running trials by instalments. It reaffirmed that, save exceptionally, a defendant cannot:

• run one case before the jury and, having lost, run a different one on appeal;
• use fresh evidence merely to shore up inadequacies or improve quality of the trial evidence;
• introduce a new expert who simply disagrees with earlier defence experts on materially the same foundation;
• develop or embellish an account post-trial to provide a platform for new expert opinions.

This principle did substantial work in the reasoning: the Court treated the new psychiatric evidence as, at best, an attempt to bolster a loss-of-control narrative that was never truly part of the defence case and lacked a factual base.

3.2 Legal Reasoning

(a) The statutory tests: loss of control (CJA 2009) and fresh evidence (CAA 1968)

The Court rehearsed the structure of the loss of control defence under section 54 of the Coroners and Justice Act 2009: (i) actual loss of self-control; (ii) a qualifying trigger (here, fear of serious violence under section 55(3)); and (iii) an objective comparator: a person of the defendant’s age and sex, with normal tolerance and self-restraint, in the defendant’s circumstances (excluding matters going only to capacity for tolerance/self-restraint).

For fresh evidence, the Court applied section 23 of the Criminal Appeal Act 1968: whether it is necessary or expedient in the interests of justice, taking into account credibility, availability at trial, reasons for non-adduction, and (decisively) whether it might afford a ground for allowing the appeal.

(b) Admissibility and probative limits of CPTSD/PTSD evidence

The Court accepted the credibility of the new psychiatric diagnosis and, notably, that the Crown’s expert agreed that Ms O’Shaughnessy suffered PTSD/CPTSD at the time. But it drew a strict boundary around relevance:

• The diagnosis could not be used to argue she should be judged by a lower standard of self-restraint (barred by the statutory structure as applied in R v Rejmanski [2017] EWCA Crim 2061).
• It could only potentially assist on the gravity of the trigger—i.e. whether the fear of serious violence could be experienced as especially grave.

The Court then treated that potential assistance as marginal on these facts: if the choking/headlock scenario were true, it would obviously amount to a fear-of-serious-violence trigger without needing expert help.

(c) Trial coherence: self-defence versus loss of control, and the centrality of factual rejection

The judgment is particularly instructive on forensic coherence. Ms O’Shaughnessy’s consistent account was controlled, purposeful self-defensive action (“grabbed the first thing” and swung to get him off), not an inability to control herself. She never asserted a loss of control to police, at interview, in proof, in evidence, or to any expert.

The Court held that loss of control would have:

• undermined the primary defence of self-defence (which sought acquittal);
• been inconsistent with her account and therefore difficult for counsel ethically and practically to run;
• risked supplying the Crown with a retaliation/revenge narrative (especially if sexual allegations were foregrounded), contrary to section 54(4)’s bar on revenge.

These were not second-guessable “missed opportunities” but justified tactical decisions. The Court also observed that the trial judge could properly have declined to leave loss of control at all, given the thin factual basis; yet he left it and directed impeccably, and the jury rejected it.

(d) Why the fresh evidence could not make the conviction unsafe

The Court’s safety analysis turned on what the jury’s verdict necessarily entailed. The jury rejected self-defence; the Court considered it “obvious” they must have disbelieved her account of being choked at the moment of stabbing. On the prosecution case (stabbing from behind as he walked away), there was no evidential platform for loss of control: no account of losing control, no explanatory narrative consistent with sudden loss, and a single controlled wound inconsistent with a frenzy.

Since the psychiatric evidence did not touch the decisive factual rejection (whether she was being attacked as alleged; whether she stabbed him from behind), it could not rationally affect the verdict. Admitting it would therefore be precisely the kind of appeal-by-reframing that R v Erskine (Kenneth) [2009] EWCA Crim 1425; [2009] 2 Cr App R 29 cautions against.

3.3 Impact

• Appeals based on updated diagnostic categories: The Court signalled that the emergence of CPTSD as a recognised diagnosis (here, post-trial) will not, without more, justify reopening verdicts. If the underlying condition (PTSD) and relevant evidence were available at trial, section 23 will be hard to satisfy.
• Firm limits on psychiatric evidence in loss of control: This decision reinforces that such evidence is generally confined to explaining trigger gravity, not reducing the objective standard of tolerance/self-restraint. Parties seeking to deploy mental health evidence must articulate the precise admissible route and expect careful directions.
• Strategic finality and trial integrity: The judgment strengthens appellate reluctance to permit reconfiguration of defences post-conviction, particularly where the alternative defence would have undermined the primary defence at trial and where the jury has already been directed on it.
• Domestic abuse context: While the Court accepted the reality of trauma and agreed diagnoses, it demonstrated that trauma evidence cannot substitute for the missing factual foundation of loss of control where the jury’s verdict implies rejection of the defendant’s account of the incident itself.