CCPR/C/124/D/2892/2016 verdict. For this reason, the Committee finds this part of the complaint insufficiently substantiated and inadmissible under article 2 of the Optional protocol. 6.5 The Committee finds the author’s claim under article 7, read alone and in conjunction with article 2 (3), of the Covenant sufficiently substantiated for the purpose of admissibility and proceeds to its consideration of the merits. Consideration of the merits 7.1 The Committee has considered the present communication in the light of all the information submitted to it by the parties, in accordance with article 5 (1) of the Optional Protocol. 7.2 The Committee notes the author’s allegation that he was tortured by police officers from the moment of his arrest on 17 February 2012 until he signed a confession late at night on the same day. In this regard, the Committee notes that the copies of the investigative documents on file refer to the medical certificate from hospital No. 4 dated 17 February 2012, which mentions that the author had bruises. The same information is reflected in the medical records of SIZO No. 1, where the author was detained. 7.3 The Committee recalls that a State party is responsible for the security of any person it holds in detention and, when an individual in detention shows signs of injury, it is incumbent on the State party to produce evidence showing that it is not responsible. 2 The Committee has held on several occasions that the burden of proof in such cases also cannot rest with the author of a communication alone, especially considering that frequently only the State party has access to the relevant information. 3 7.4 The Committee notes that the State party did not refute the author’s allegations with reference to proper documentary or other evidence. Taking into account the detailed information provided by the author about his treatment by police officers upon arrest, including the names of those officers, the bruises on the author’s shoulders, his claim that the police officers forced him to make a false statement about the nature of his injuries to the general practitioner during the medical check-up in city hospital No. 4, as well as the lack of a sufficient explanation to the contrary from the State party, the Committee finds a violation of the author’s rights under article 7 of the Covenant. 7.5 The Committee notes the author’s further claim that the investigation in his case was ineffective. The Committee recalls that once a complaint about ill-treatment contrary to article 7 has been filed, a State party must investigate it promptly and impartially so as to make the remedy effective. 4 In the present case, the Committee notes that the author’s mother submitted to the Pervomaysky district prosecutor’s office a complaint alleging torture of the author on 17 April 2012. The investigation was started and the decision not to open a criminal case was made by the prosecutor on 25 April, i.e. one week after receiving the complaint. The Committee also notes, however, that over a period of two years the investigation was reopened eight times; the instructions set out in the decisions to reopen the investigation were not carried out; the witnesses indicated by the author and his mother were not questioned; and a forensic examination was not carried out despite a medical certificate showing that the author had bruises on his body. Given these circumstances, it can be said that although the investigation may have started promptly, it was not concluded in a timely manner. 7.6 As to the impartiality of the investigation, the Committee notes the author’s allegations that only the police officers who arrested him were questioned during the initial investigation, that the prosecutor’s office did not locate and question his cellmates from 2 3 4 6 See, e.g., Eshonov v. Uzbekistan (CCPR/C/99/D/1225/2003), para. 9.8; Siragev v. Uzbekistan (CCPR/C/85/D/907/2000), para. 6.2; and Zheikov v. Russian Federation (CCPR/C/86/D/889/1999), para. 7.2. See, e.g., Mukong v. Cameroon (CCPR/C/51/D/458/1991), para. 9.2; and Belier v. Uruguay (CCPR/C/15/D/30/1978), para. 13.3. See general comment No. 20 (1992) on the prohibition of torture or other cruel, inhuman or degrading treatment or punishment, para. 14; and, for example, Neporozhnev v. Russian Federation (CCPR/C/116/D/1941/2010), para. 8.4.