In its most recent history, Kingston Penitentiary provided accommodation to a static inmate population classified at the maximum-security level, many of whom could not safely integrate into other institutional populations. Additionally, the Temporary Detention Unit was relocated from Millhaven Institution to Kingston Penitentiary in February 1998. This unit consisted of a range of cells with the capacity for 37 offenders who had been readmitted under Temporary Detention status in the Ontario Region. More than 1000 offenders were re-assessed annually for placement at a parent institution by this unit. The Regional Hospital, which provided twenty-four-hour palliative nursing care, was also on site, as was the Regional Treatment Centre, an independently managed facility providing in-house mental health and treatment services to the Ontario regional population.
Within the general population, convictions ranged across the broad spectrum of Canadian Criminal Code offences. The population represented a cross-section of the multi-cultural/religious mosaic of Canadian society. There were a number of foreign nationals incarcerated at Kingston Penitentiary with the majority of them being subject to a Deportation Order upon release. Most of Canada’s more notorious inmates have been held at Kingston Penitentiary over the years.