Actuarial risk assessment tools have been part of the initial security classification process in Canadian prisons since the 1990s. Developed initially on a white, homogenous male prison population (Hannah-Moffat, 2015b), actuarial instruments have been championed by researchers in the field of corrections and psychology as an “objective” instrument that can standardize the classification procedure (Andrews et al., 1990; Barnum & Gobeil, 2012). However, the universal application of such tools has been met with resistance, criticized for having not been validated on an Indigenous prison population and thus culturally inappropriate for use (Martel et al., 2011; Monture-Angus, 1999; Webster & Doob, 2004). This thesis intends to examine how Correctional Service Canada (CSC) has legitimated the use of actuarial tools in its initial security classification and penitentiary placement procedure. Guided by the theoretical framework of governmentality (Foucault, 1991) and the logic of elimination (Wolfe, 1994; 2006), this study undertakes a qualitative content analysis of seven CSC research documents that evaluated the empirical validity and reliability of the Custody Rating Scale (CRS), a 12-item structured instrument that calculates a prisoner’s recommended security classification level. I put forth the argument that, in the process of legitimating actuarial instruments by appealing to justifications grounded in an actuarial rationality, CSC simultaneously facilitates the ontological erasure of Indigenous people in prison that is consistent with a logic of elimination inherent in settler colonial societies.