Criminal justice education is a relatively new program in higher education in many countries, and its curriculum and parameters remain unsettled. An exploratory study investigated whether threshold concepts theory provided a useful lens by which to explore student understandings of this multidisciplinary field. Eight high-performing final-year students in a Bachelor of Criminology and Criminal Justice degree were invited to identify and reflect on one powerful concept that helped them make sense of the field. Analysis indicated three subgroups with different conceptual encounters. There was evidence that multidisciplinary professional fields are characterised by bounded and unbounded generic thresholds. While the article comments on current criminal justice education, it raises concerns for multidisciplinarity and threshold concepts research more broadly. (Contains 1 table.)