Interviews were undertaken with participants drawn from four groups: police detectives; criminal lawyers; young people in the community (aged 25 and under); and prisoners, convicted when young (aged 25 years old and under) of serious violence using the principles of joint enterprise. The questions focused on: individual’s life histories (for practitioners this focused on their professional histories); young people's social relations; experiences of violence; for the practitioners, the process of investigating cases of serious ‘group-related’ violence involving young people; understandings and perceptions of joint enterprise and the law related to serious violence; and – for practitioners – perceptions of young people’s understandings of the law. Joint enterprise is the term given to a complex set of legal principles, which allow for more than one person to be convicted of a single offence. Research on joint enterprise is limited, but have raised concerns about its disproportionate use against young black and mixed race men, which has been blamed on racist prosecution and policing strategies, and the perceived lack of legitimacy of joint enterprise among those convicted using its principles. The goal of the study is to make a theoretical and empirical contribution to the debate on joint enterprise as a legal response to serious group violence involving young people, to inform policy makers, criminal justice practitioners and young people themselves. Within this, there are four central aims: to provide an analysis of young people’s social relations and how these influence and shape their involvement in serious group violence; to document young people’s perceptions and experiences of the law, as it relates to serious violence generally and joint enterprise specifically; to provide an analysis of criminal justice practitioners’ interpretations of young people’s social relations and the extent to which these influence practice in cases of serious group violence; and to document criminal justice practitioners’ legal consciousness and explore the impact of recent changes to joint enterprise on practice. The research involves interviews with criminal justice practitioners (police detectives and lawyers), prisoners convicted using the principles of joint enterprise and young people in the community.

Semi-structured interviews were undertaken with four samples. In total,participants included: - 41 legal practitioners with experience of working on cases of multi-handed violence. Purposive samples of Homicide and 'Gang' police detectives and prosecution and defence lawyers were obtained, based on their experience of investigating cases of multi-handed serious violence involving young people in London, UK. - 36 prisoners who, between the ages of 16 and 25 years, were convicted of serious violence using the principles of joint enterprise. A purpose sample were obtained from three prisons in England - one adult male prison, one young offender institution and one female prison; and - 56 young people in the community, aged between 16 and 25 years old, with various experiences of serious group violence (from no experience to considerable involvement as witnesses, victims and perpetrators). Young people were sampled from third sector organisations working with young people, a further education college and a youth offending team in London.