27 [t]he essential purpose of such investigation is to secure the effective implementation of the domestic laws which protect the right to life and, in those cases involving State agents or bodies, to ensure their accountability for deaths occurring under their responsibility […]. For an investigation into alleged unlawful killing by State agents to be effective, it may generally be regarded as necessary for the persons responsible for and carrying out the investigation to be independent from those implicated in the events. […] The next-of-kin of the victim must be involved in the procedure to the extent necessary to safeguard his or her legitimate interests. […] A requirement of promptness and reasonable expedition is implicit in this context […] The investigation must also be effective in the sense that it is capable of leading to a determination of whether the force used in such cases was or was not justified in the circumstances [or was] unlawful […] There must be a sufficient element of public scrutiny of the investigation or its 92 results to secure accountability in practice as well as in theory. 140. In the instant case, the Commission has taken as proven fact that José Luis García Ibarra, age 16, was killed on September 15, 1992, by a bullet fired from a weapon in the hands of police officer Guillermo Segundo Cortez Escobedo. As the Commission explained earlier, there are essentially two main versions of the events surrounding the death of the adolescent García Ibarra. The version given by the victim’s mother and the majority of the eyewitnesses indicates that the shot was fired deliberately and aimed at the adolescent; on the hand, the version given by the police office and a smaller group of witnesses is that there was a struggle between the police officer and young Segundo Rafael Mosquera Sosa. According to the police officer, this struggle caused the gun to accidentally fire, killing José Luis García Ibarra. 141. The Commission observes that no one contests the fact that the person who fired the shot that killed José Luis García Ibarra was an agent of the State who used his official weapon against the adolescent. The Commission notes that at some point of the investigation it was referred to the fact that officer Cortez was drunk which could lead that he was not on duty. However, on this point, the Commission notes that the State itself in its communications during the Inter-American procedure expressly acknowledged that Mr. Cortez had been on duty for the day and time of the incident. Also, as noted in the finding facts, during the domestic investigation it was provided a certificate from the Police Command stating that at the time of the child's death García Ibarra was on duty for 24 hours. 142. In any case, the Commission emphasizes that the possible situation of inebriate of a police officer does not modify the analysis of the State’s international responsibility. 143. On this point, in the case Bugara v. Ukraine, the European Court of Human Rights indicated that while private acts of a police officer could not at first engage the State's responsibility under the right to life, there are certain cases in which it could declare its responsibility93. For example, the European Court stated in the case cited that when a police officer is not wearing a uniform and is off duty, its condition of State’s agent is activated if it is involved in a police operation or spontaneous 92 ECHR. Hugh Jordan v. the United Kingdom, no. 24746/94, §§ 105-109, 4 May 2001; Douglas-Williams v. the United Kingdom (dec.), no. 56413/00, 8 January 2002. 93 ECHR. Gorovenky and Bugara v. Ukraine. 12 April 2012. Citando. ECHR. Celik v. Turkey (No. 2). 27 May 2010; Enukidze and Girgvliani v. Georgia. 26 April 2011.