The old PPC were closed due to (1) their location being disclosed to the outside world, (2) the construction of vital facilities nearby, or (3) the PPC’s integration with other similar facility for administrative purposes. Information pertaining to the opening, relocation or closure/integration of PPC is generally drawn from witness testimonies. However, the relatively small number of available testimonies has limited our understanding of the finer details of PPC operation. A number of testimonies relate to closure of many PPC in the past, however, provide no information about any case of release of prisoners in large numbers. Some prisoners may have been released during the process of PPC closure but it appears that most, if not all, were transferred to another PPC. In summary, the overall size of individual PPC may have been reduced at times, but the system has largely remained unchanged over the years in terms of the size and capacity of PPC. 40