Dev read Law at the University of Bristol, receiving his LL.B. (First Class Honours) in 2007. He spent much of the next five years teaching in London, primarily as a private tutor, but also undertaking one-to-one teaching in secondary schools. Dev was also a member of the Zahid Mubarek Trust (2010), conducting research on bullying and victimisation within Young Offenders' Institutes, and on deaths arising from cell-sharing. In 2012 he began his MPhil in Criminological Research at the Institute of Criminology on an ESRC 1+3 studentship; he completed his MPhil in 2013. Dev's MPhil thesis, titled 'Gangs Behind Bars: Fact or Fiction?', was a qualitative study of English prison gangs, exploring the links between gangs in prison and their street counterparts.
Dev's PhD research continues to study prison gangs in England, with a particular focus on how religious extremism and racial identity affect prison gang membership. This includes studying the development of street gang allegiances within prison, as well as the impact of religious extremism on prisoner groupings. Dev is supervised by Professor Alison Liebling at the Institute of Criminology Prisons Research Centre.