28 CFR 540.201: Designation criteria.

Inmates may be designated to a CMU if evidence of the following criteria exists:

(a) The inmate's current offense(s) of conviction, or offense conduct, included association, communication, or involvement, related to international or domestic terrorism;

(b) The inmate's current offense(s) of conviction, offense conduct, or activity while incarcerated, indicates a substantial likelihood that the inmate will encourage, coordinate, facilitate, or otherwise act in furtherance of illegal activity through communication with persons in the community;

(c) The inmate has attempted, or indicates a substantial likelihood that the inmate will contact victims of the inmate's current offense(s) of conviction;

(d) The inmate committed prohibited activity related to misuse or abuse of approved communication methods while incarcerated; or

(e) There is any other substantiated/credible evidence of a potential threat to the safe, secure, and orderly operation of prison facilities, or protection of the public, as a result of the inmate's communication with persons in the community.