- 41 authorities to prisoners in their charge includes the responsibility to protect them from other prisoners who might wish to cause them harm. In particular, prison staff must be alert to signs of trouble and be both resolved and properly trained to intervene. Such a capacity to intervene will of course depend inter alia on an adequate staff/prisoner ratio (cf. also paragraph 97 below). In addition, the prison system as a whole may need to develop the capacity to ensure that potentially incompatible categories of prisoners are not accommodated together. Further, prison staff are unlikely to be able to protect prisoners if they fear for their own safety or if they lack effective management support. These issues should be openly addressed in initial, in-service and ongoing training programmes for staff of all grades. Tackling effectively the problems posed by inter-prisoner violence requires the implementation of an individualised risk and needs assessment, the availability of sufficient members of staff and ensuring that staff receive the requisite initial and advanced training throughout their careers. In the light of these remarks, the CPT recommends that the Greek authorities devise a national strategy concerning inter-prisoner violence. 3. Conditions of detention a. material conditions 84. The general characteristics of Korydallos Prison Complex have been described in previous visit reports24. As regards Korydallos Men’s Prison the official capacity now stands at 640, compared with 780 in 2001, while the inmate population remains around 2,100. At the time of the delegation’s visit there were 962 persons on remand and 1,138 sentenced prisoners. 85. The delegation was informed about ongoing efforts to maintain the material conditions in the prison at a satisfactory level. While such repairs are essential they are, in themselves, insufficient to render the conditions acceptable as long as the occupancy level remains at three or four persons for cells of 9.5m². While it is unrealistic to expect the occupancy level to be reduced to one person per cell as foreseen when the prison was constructed, serious efforts should be made to reduce the number to no more than two prisoners per cell. The phenomenon of overcrowding in Korydallos Men’s Prison is neither new nor temporary. In the meantime additional resources need to be made available to cope with the increased wear and tear of the facilities, which is inevitable when so many persons are confined in such cramped conditions. 24 cf. CPT/Inf(94) 20, paragraph 91; CPT/Inf (2001) 18, Part I, paragraph 106 and Part II, in paragraph 52.