Blog 28th Apr 2021

The Court of Appeal restates a robust approach to secondary parties in homicide cases.

Two recent Court of Appeal cases demonstrate the robust approach taken by the Court to secondary parties in homicide cases involving group violence between young men in public using weapons. In the context of such offences, the Court has emphatically restated the limited circumstances in which the principle of ‘Overwhelming Supervening Act’ might assist a secondary party’s defence (Lanning & Anor [2021] EWCA Crim 450); and emphasised the narrow distinction to be drawn between the culpability of principals and secondary parties convicted of murder (R v Semusu & Anor [2021] EWCA Crim 513). Both cases reflect developments in the law as result of the landmark decision of the Supreme Court in R v Jogee [2016] UKSC 8.

Homicide cases involving armed, public, group violence between young men are tragically frequent occurrences. The recent Office for National Statistics’ analysis of the Home Office’s Homicide Index makes for sobering reading[1]: for the year ending March 2020, the homicide rate for males was three times that for females; the most common age group for a victim of homicide was 16-24 years old; there were 275 recorded homicides using knives, the second highest annual total since the Homicide Index began in 1946, and only six fewer than the peak in year ending March 2018.

The limits of ‘Overwhelming Supervening Act’

The principle of Overwhelming Supervening Act (‘OSA’) limits the liability of secondary parties in homicide cases where the actions of the principal are sufficiently extraordinary to break the chain of causation between the two parties.

In Lanning & Anor, the court upheld the convictions of Camille, for manslaughter and Lanning for murder, in relation to the killing of Tashan Daniel at Hillingdon Underground Station on 24 September 2019. At the time of the fatal assault Lanning was 21, Camille 19, and Daniel 20.

The stabbing of Tashan Daniel occurred during an outbreak of spontaneous violence at the station. Lanning had exchanged words with Daniel and his friend, Campbell, who were on the opposite platform across the train tracks. After a few seconds, Lanning crossed the footbridge linking the platforms to confront the pair. As he did so he was joined by Camille. Lanning and Camille immediately confronted Daniel and Campbell. The assault itself lasted a matter of seconds: Lanning struck the first blow, punching Campbell. A fight ensued, and then split into two parts, with Lanning facing off against Daniel and Camille against Campbell. Lanning pulled out a knife and delivered a fatal blow, stabbing Daniel in the chest. Almost immediately after the fatal blow was struck, Lanning and Camille ran from the station. Together, they concealed their bloodstained clothes, and the knife, in a nearby housing estate. The two men were arrested together two weeks later.

Camille argued at first instance that the jury ought to be directed to consider whether the production of the knife by Lanning during the assault (a weapon of which Camille was unaware) in the circumstances of spontaneous violence might amount to an OSA. The prosecution argued that it would be contrary to the developments in the law since Jogee to leave OSA to the jury: it was clear that knowledge of a weapon was only evidence relevant to the question of a secondary party’s intent. On the facts, there was simply no evidential basis for the jury to conclude that an OSA existed. HHJ Dennis QC, the judge at first instance, agreed with prosecution. Camille appealed his conviction on the basis that the judge ought to have left the question of OSA to the jury.

The Court of Appeal (in a judgment delivered by the Vice President of the Court of Appeal) concluded that there was no evidential basis for the question of OSA to be left to the jury. Giving judgment, Fulford LJ considered the development of the principle since Jogee in the subsequent cases of Tas [2018] EWCA Crim 2603 and R v Harper [2019] EWCA Crim 343. The Court endorsed the approach taken in those cases, each of which emphasised the limited circumstances in which the question of an OSA might genuinely arise.


Fulford LJ made the following observations:

  1. …. As the Crown suggest, “in today’s social climate”, or, as we would put it, bearing in mind that knives are produced in situations of this kind with a high degree of frequency leading to serious injury or death, the judge was entitled to conclude that there was an insufficient factual basis for a jury to conclude … that “nobody in the defendant’s shoes could have contemplated” that the production and use of a knife in the joint attack might happen. It was open to the judge to determine that the production of the knife was not an event of such a character as to relegate JC’s acts of encouraging AL to assault the two victims to history.
  1. We stress that we consider it is essentially irrelevant in this regard that JC was unaware of the presence of the knife …What matters instead is whether JC intended to assist AL in a crime where some physical harm would be caused to the victims…
  1. … Given that the effect of Jogee is that in cases of this kind knowledge of a weapon has been relegated to proof of intent, we do not consider that in the present context its production meant that an OSA should have been left to the jury. Indeed, the harm by AL could have been caused by forcing the victim to the ground or onto the railway tracks, so that he fatally hit his head. This wholly unnecessary fatality was a paradigm of rapidly escalating violence which was part of a joint enterprise attack. In the circumstances we are unpersuaded by this ground of appeal.


Fulford LJ’s observation about the relevance of the broader context of the use of knives in “situations of this kind” is borne out by the statistics. Although each case will turn on its own facts, that context undoubtedly provides a sound basis for the Court all but excluding the question of OSA in circumstances of group violence in public between young men using weapons.  If there was any remaining doubt as to the strict limits placed on the application of the principle of OSA by the higher courts, it has surely now been dispelled.

Relative culpability of principals and secondary parties

In R v Semusu & Anor the Attorney-General sought to refer two sentences for murder to the Court of Appeal as being unduly lenient. In December 2020 Nami and Semusu were convicted of the murder of Tcherno Ly who had been stabbed to death in a crowded street at the Leeds Carnival. The trial judge sentenced Nami to life imprisonment with a minimum term of 20 years for murder, and he also received a concurrent term of two years’ imprisonment for possession of an offensive weapon. Semusu was sentenced to life imprisonment with a minimum term of 16 years for murder. The Court of Appeal did not interfere with Nami’s sentence (although it was observed that it was towards the bottom of the appropriate sentencing bracket), but quashed Semusu’s minimum term of 16 years and substituted it for one of 19 years.

Nami and Semusu spent the 25 August 2019 together at the Leeds Carnival. Later that evening they sought out Mr Ly, who had been involved in previous violence with Nami. Nami was, by the time of the fatal incident, armed with the murder weapon and Semusu knew that he was in possession of the knife: a large Rambo style knife. Nami and Semusu spotted Mr Ly and Nami confronted him. Mr Ly was also armed with a large knife, which he produced. Mr Ly struck the first blow when the fight broke out by stabbing Nami twice, causing minor injury as he stepped aside to avoid the blows. Nami then stabbed Mr Ly once, penetrating the abdomen with such force that the blade passed through all the soft tissue structures of the body, before lodging in his spinal column. Whilst Nami and Mr Ly were fighting, Semusu was struggling with Mr Ly’s friend thus preventing him from coming to Mr Ly’s assistance – at no point did Semusu use any violence towards Mr Ly.  After Mr Ly had been stabbed, Nami and Semusu fled the scene. Nami washed the knife and the two attackers changed their clothing. Having changed their appearance, they then returned to the carnival. At the time of the murder, the two offenders were both only 19 years old. The victim, 21.

The Court found that the trial judge, Cavanagh J, had correctly identified the starting point of 25 years for both offenders under paragraph 4 of schedule 21 of the Sentencing Act 2020, Nami having brought a knife with him to the scene. The Court further agreed that the age of the offenders provided significant mitigation to both.

Edis LJ, giving judgment, made the following observations in respect of the culpability of secondary parties convicted of murder in the context of cases such as Semusu’s i.e. those of group violence between young men in public using weapons:

  1. In sentencing for joint offences, the provisions of Schedule 21 apply to secondary participants as well as principal offenders, but there might properly be a distinction between the minimum terms to reflect the lesser culpability of the secondary party (See Attorney General’s Reference (No. 24 of 2008), R v Sanchez [2008] EWCA Crim 2936). That, though, is because the culpability of a secondary party may be less than that of a principal offender (see paragraph 33):

“Although the culpability of the secondary party may in many cases be less than the principal, the sentences must be viewed proportionately in the light of the policy of the law, that he who encourages the commission of a murder or assists with the commission is to be dealt with as a murderer.”

  1. The number of cases of the present kind where there is a wide gap between the culpability of the principal offender and that of the secondary party has been reduced by the decision of the Supreme Court in R v Jogee. The person who encourages or assists the principal merely foreseeing that he might intentionally cause death or really serious harm is not guilty of murder. In the modern law the secondary party must encourage or assist the principal intending that the principal will intentionally cause death or really serious harm. That is the basis on which Semusu was convicted. He was acquitted of the count of possession of an offensive weapon. We suppose this means that the jury was not sure that Semusu had been any part of the expedition by Nami to arm himself for the fight and that he arrived at the scene at a somewhat later point than Nami had done. Nevertheless, the jury’s verdict means that he knew that Nami had that knife before he produced it and that he knew that it was to be used, and assisted in or encouraged that use.

In the light of that discussion, the Court considered whether the trial judge had drawn too great a distinction between the principal offender and the secondary party in terms of culpability, and concluded that there was no reason to find that his culpability was markedly less than that of Nami in what was truly a joint attack with a shared murderous intention. The Court found that given the defendant’s previous convictions, his failure to respond to previous sentences and his history of involvement with knives it would have imposed a higher minimum term than the 20 years imposed by the trial Judge.

It is difficult to disagree with the Court’s logic. Pre-Jogee, the range of culpability which might properly be attributed by a sentencing judge to a secondary party convicted of murder was broader, precisely because the mental element required to establish was also broader. The effect of Jogee was to limit secondary party liability in murder cases to circumstances where the secondary party can be proven to have had the same murderous intention as the principal. As a consequence, if that is proven then there is no basis to draw a significant distinction between the culpability of the principal and the secondary party simply because the secondary party did not strike the fatal blow (or any blow for that matter).


Oliver Glasgow QC and Will Martin were instructed in Lanning by the Appeals and Review Unit of the CPS Special Crime and Counter Terrorism Division.

Oliver Glasgow QC was instructed in Semusu by the AGO and the Appeals and Review Unit of the CPS Special Crime and Counter Terrorism Division.


[1] Published 25 February 2021

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