Dr John Taggart is a Lecturer in Law and Director of the Institute of Criminology and Criminal Justice at Queens' University, Belfast. John is also a qualified barrister in Northern Ireland and England and Wales and has practised criminal law in both jurisdictions. His research focuses on the criminal process, criminal justice and socio-legal approaches to criminal law. In particular, John's research looks at special measures in criminal courts and the role of the intermediary as a communication specialist for vulnerable court users.

John is the theme lead for the 'Vulnerable Accused' as part of the British Society of Criminology Vulnerability Research Network. He co-convenes the 'Vulnerable Suspects and Defendants work-in-progress forum' and has recently been appointed to the Advocate's Gateway Management Committee. John is a regular adviser to the Department of Justice (Northern Ireland) and has trained intermediary cohorts in both Northern Ireland and the Republic of Ireland.

John's current research project focuses on the conceptualisation of the right to 'effective participation' in police custody. As part of this project, John is collaborating with the Department of Justice (Northern Ireland), the Police Service of Northern Ireland (PSNI) and the Public Prosecution Service of Northern Ireland (PPS). John’s first monograph, ‘The Intermediary in the Criminal Justice System’ was published by Routledge in 2025.