A/HRC/15/50 their members should not be unduly influenced by powerful social groups, such as the media, industry or political parties.17 23. Impartiality. Impartiality is closely related to independence. While independence relates to the establishment and functioning of an investigative body and its members, impartiality refers to the question of whether an investigator is or is likely to be biased. The Human Rights Committee has stated that “judges must not harbour preconceptions about the matter put before them, and that they must not act in ways that promote the interests of one of the parties”.18 Similar considerations apply to investigators. Indications that investigators uncritically adhere to one interpretation of events without bothering to explore alternatives, including the version of events advanced by the complainant, or fail to acknowledge a lack of evidence to support their interpretation of events, could indicate a lack of impartiality.19 24. Thoroughness and effectiveness. This standard refers to the completeness and comprehensiveness of an investigation. Thorough and effective investigators should: undertake necessary autopsies and medical examinations; collect and record all relevant evidence; conduct site visits as appropriate; identify, question and take statements from all relevant witnesses; question witnesses comprehensively so that the investigation is able to establish the cause of the alleged violation and those responsible; and provide conclusions based on a comprehensive analysis of all relevant elements.20 The Committee against Torture has found that inconsistencies in the results of investigations, as well as a lack of qualifications of key experts, such as the doctor undertaking an autopsy, can be evidence of a lack of thoroughness.21 25. Promptness. As a general rule an investigation should commence and progress with reasonable expedition.22 Determining whether an investigation has met this standard of reasonableness depends on the specific circumstances of the case. Cases of torture and extrajudicial killings – where medical evidence might disappear – and enforced disappearances – where an individual’s life might be in imminent danger – require immediate action. The Committee against Torture suggests that the requirement to undertake a prompt investigation means that an investigation should be initiated immediately when there is a suspicion of torture or ill-treatment, namely, within hours or days.23 It has found delays of 15 months and 10 months between the alleged act and the 17 18 19 20 21 22 23 8 Manfred Nowak, U.N. Covenant on Civil and Political Rights: CCPR Commentary, 2nd rev. ed. (N.P. Engel, 2005), pp. 320–321. Karttunen v. Finland, communication No. 387/1989, views of 23 October 1992, para. 7.2. European Court of Human Rights, Assenov and Others v. Bulgaria, Judgement, 28 October 1998, para. 103. European Court of Human Rights, Musayev and Others v. Russia, application Nos. 57941/00, 58699/00 and 60403/00, Judgement, 26 July 2007, para. 162; Gül v. Turkey, Case 22676/93, Judgement, 14 December 2000, para. 89–90; Cennet Ayhan and Mehmet Salih Ayhan v. Turkey, application No. 41964/98, Judgement, 27 June 2006, para. 88; Nachova and Others v. Bulgaria, application Nos. 43577/98 and 43579/98, Judgement, 6 July 2005, para. 113. Ristic v. Yugoslavia, communication No. 113/1998, views of 11 May 2001, para. 8.6. See also European Court of Human Rights, Kopylov v. Russia, application No. 3933/04, Judgement, 29 July 2010, para. 169; Akulinin and Babich v. Russia, application No. 5742/02, Judgement, 2 October 2008, para. 51. European Court of Human Rights, Isayeva, Yusupova and Bazayeva v. Russia, application Nos. 57947/00, 57948/00, 57949/00), Judgement, 24 February 2005, paras. 209–213; Benuyeva and Others v. Russia, application No.8347/05, Judgement, 22 July 2010, para. 112. Blanco Abad v. Spain, communication No. 59/1996, views of 14 May 1998, para. 8.5.