Article 13 Each State Party shall ensure that any individual who alleges he has been subjected to torture in any territory under its jurisdiction has the right to complain to, and to have his case promptly and impartially examined by, its competent authorities. Steps shall be taken to ensure that the complainant and witnesses are protected against all illtreatment or intimidation as a consequence of his complaint or any evidence given. The development of an underlying set of principles which informed approaches to police oversight derived from the requirements and obligations set out in; x UNCAT; x ECHR; x judgements of the Court over a period of several years; and, x statements and interpretations laid out by the European Committee for the Prevention of Torture and Inhuman or Degrading Treatment or Punishment (CPT); The Court developed five key principles for the effective investigation of complaints against the police that engage Article 2 or 3 ECHR: x Independence; no institutional or hierarchical connections between the investigators and the officer subject of the complaint, amounting to a real, practical independence3; x adequacy; the investigation should be capable of gathering evidence to determine whether police behaviour complained of was unlawful and to identify and punish those responsible4; x promptness; the investigation should be conducted promptly and expeditiously in order to maintain confidence in the rule of law 5; x public scrutiny; procedures and decision-making should be open and transparent in order to ensure accountability; and, x victim involvement; the complainant should be involved in the complaints process in order to safeguard his or her legitimate interests. Giving effect to the obligations set out in the ECHR and UNCAT required the Court to further define the obligations placed on States to carry out effective investigations in pursuit of the ‘adequacy’ principle. For example, separating compensation and damages for violations of Article 3 from effective criminal 3 Halat v. Turkey, (23607/08) – judgement of 8 November 2011 and Mocanu and others v Romania (10865/09, 45886/07 and 32431/08) – judgement of 17 September 2014 4 Aksoy v Turkey (Application no. 21987/93) – judgement of 18 December 1996; Alder v United Kingdom (42078/02) judgement of 22 November 2011 5 Aydin v. Turkey (57/1996/676/866) – judgement of 25 September 1997 5