‘Secondary suspects’ in joint enterprise murder convictions have seen a dramatic increase in sentence lengths over the last decade, with their time in prison rising by over a third for the same crime.

Controversial joint enterprise convictions allow for multiple parties to be convicted of one murder, even when only one person made the fatal blow upon the victim. It has seen, in particular, young black men swept up in murder convictions for simply being present at the scene of the crime but taking no action. They have been described as a racist ‘legal dragnet’ with convictions often relying on false narratives about gang involvement.

New research from the Centre for Crime and Justice Studies has uncovered that in 2012 only 7% of secondary suspects convicted of manslaughter received a prison sentence of over ten years (not including life sentences). By 2022, this had risen to 42%. The researchers say this represents a convergence of two phenomena in the criminal justice system: Significant sentence inflation across the board, and an increase in multi-defendant or joint enterprise trials.

They have urged the government to adjust sentencing so that secondary parties are no longer subject to the same labelling of their offence and mandatory sentence lengths as the principal offender. They say this is achievable through ‘explicitly recognising’ their secondary status as a mitigating factor at sentencing.

Currently three or more defendants are charged in almost 10% of murder cases. In the early 1980s this was only 3%, and in the 1960s multi-defendant murder cases were noted as being ‘exceptional’. The numbers also reveal an absolute increase: In 1984 there were 18 such cases, and in 2024 there were 54. There has also been a sustained rise in the number of multi-defendant murder trials since the early 2000s.

Analysis highlighted in this report also shows that the overuse of joint enterprise by prosecutors in contributing to the massive backlog in the criminal courts. Courtwatch research found that some of the most delayed and ‘resource-intensive’ cases at the Central Criminal Court in 2024 and 2025 were multi-defendant joint enterprise prosecutions involving children and
young people – many of whom were later acquitted or did not receive a prison sentence. They highlighted a vicious cycle: joint enterprise prosecutions produce long trials, which prolong remand
periods, expose even more young people to the harms of being imprisoned while on remand, and further intensify court delays.

The lead author of this research, Liat Tuv, said: ‘For those who have long held concerns about joint enterprise, these new stats may not say much that they didn’t already know or suspect. But they do confirm some troubling trends at a time when joint enterprise is under scrutiny. In this report, we contend that the way multi-defendant cases are approached is susceptible to contemporary policy concerns. Reforming the law will take political will.’