In 2014, Stephen Harper's Conservative government introduced the Not Criminally Responsible Reform Act. Amongst the handful of changes instituted by the legislation, the Act created the "high-risk accused" designation that, when applied, heightens measures in the detention of the accused and transfers authority for their release from provincial review boards to criminal courts. While the new laws reflect the Harper government's "tough on crime" policy, they also point to the Not Criminally Responsible on Account of Mental Disorder (NCR) subject who, within the broader history of Canadian insanity law reform efforts, is unique in its ontological stability and governability. This dissertation historicizes Canada's NCR subject by investigating the often-overlooked period that preceded its introduction in 1992. By examining a variety of historical materials related to the country's insanity law reform efforts during the second half of the 20th century, this project reveals that developments during this period played an important role in constructing the governable NCR subject of today. Initially driven by the psy-entific optimism of the post-World War II era, failed efforts to reform the country's insanity laws grew increasingly problematic in the context of a number of changes, including the abolition of capital punishment, the deinstitutionalization of the psychiatric hospital, and a growing rights movement. In light of these mounting pressures, and combined with a move towards neoliberal rationalities of government in Canada beginning in the late 1960s, insanity law reform efforts shifted from attempts to decipher who the insane subject was, to questions regarding the best legal procedures and practices of its detention. In so doing, those deemed insane in the criminal legal context were increasingly understood as rights-bearing subjects that were amenable to constitutional logics. As a result, the NCR subject of today—who is ontologically stable and manageable through risk-based governance—can be understood as a product of this history.