103 CMR 421.09
Placement or Retention of an Inmate in a DSU
An inmate may be placed or retained in a DSU only after a finding by the Commissioner based on
substantial evidence that, if confined in the general population of any state correctional facility:
(1) The inmate poses a substantial threat to the safety of others; or
(2) The inmate poses a substantial threat of damaging or destroying property; or
(3) The inmate poses a substantial threat to the operation of a state correctional facility.
An inmate may be placed or retained in a segregation unit only for administrative, and not for
disciplinary, reasons.