The system under investigation in this exploratory paper is that administered by the Provisional I.R.A. in Catholic West Belfast. Many parallels between the system administered by the I.R.A. and the State system are identified, including the determinants of sentence and recognised mitigating factors. The crucial difference of due process in the State system is identified, together with the riposte of Sinn Fein that due process is effectively preempted in the State system by the pre-trial actions of the security forces. (Author abstract)