Independence 63. The existence of an IPCB with comprehensive responsibilities for oversight of the entire police complaints system makes an important contribution to the independence principle. IPCB responsibility for recording and allocation of the procedure for handling a complaint is fully compliant with the expectation that in addition to practical independence there should be a lack of institutional or hierarchical connection between investigators and the officer complained against.229 Established criteria will be required to determine who is to be responsible for the investigation of a complaint and who is to carry it out. 64. The seriousness of a complaint, in terms of the complainant’s experience, the consequences for the officer complained against and the public interest, play an important part in determining who should have responsibility for an investigation. 65. Resources will be a factor in determining which organisation, the police or IPCB, should carry out the investigation and bear most of the costs. 66. Examples of arrangements for IPCB and police co-operation in accordance with the independence principle, seriousness of the complaint and resource management implications, include: ff IPCB to have responsibility for the investigation of a complaint carried out by IPCB investigators in which Article 2 or 3 of the ECHR is engaged;230 ff IPCB to have responsibility for the investigation of a complaint that may be carried out by IPCB or police investigators in which an issue of criminal culpability arises; ff IPCB or police may have responsibility for the investigation of a complaint that may be carried out by IPCB or police investigators in which an ECHR right or freedom, except Articles 2 and 3, is engaged or an issue of disciplinary culpability arises; ff a complaint alleging poor or inadequate police performance, if appropriate for investigation, to be the responsibility of the police and carried out by police investigators; 229. See, for example, Ramsahai v. The Netherlands (Application no. 52391/99), Judgment 15 May 2007, § 325. 230. See, for example, Ramsahai v. The Netherlands (Application no. 52391/99), Judgment 15 May 2007, §§ 337 - 340. Effective investigation of ill-treatment – Guidelines ► Page 96