64. As regards the Convention requirements relating to the effectiveness of an investigation, the Court has held that it should in principle be capable P.M. v. BULGARIA JUDGMENT9of leading to the establishment of the facts of the case and to the identification and punishment of those responsible. This is not an obligation of result, but one of means. The authorities must have taken the reasonable steps available to them to secure the evidence concerning the incident, such as witness testimony and forensic evidence, and a requirement of promptness and reasonable expedition is implicit in this context (see Denis Vasilyev v. Russia, no. 32704/04, § 100, 17 December 2009, with further references). The promptness of the authorities’ reaction to the complaints is an important factor (see Labita v. Italy[GC], no. 26772/95, §§ 133 et seq., ECHR 2000-IV). Consideration has been given in the Court’s judgments to matters such as the opening of investigations, delays in identifying witnesses or taking statements (see Mătăsaruand Saviţchiv. Moldova, no. 38281/08, §§ 88 and 93, 2 November 2010), the length of time taken forthe initial investigation (see Indelicato v. Italy, no. 31143/96, § 37, 18 October 2001), and unjustified protraction of the criminal proceedingsresulting in the expiry of the statute of limitations (see Angelova and Iliev v. Bulgaria, no. 55523/00, §§ 101-103, 26 July 2007)