ERGI JUDGMENT OF 28 JULY 1998 20 (b) in order to effect a lawful arrest or to prevent the escape of a person lawfully detained; (c) in action lawfully taken for the purpose of quelling a riot or insurrection.” 69. The Government contested the applicant’s allegation (see paragraphs 16-17 above), whereas the Commission considered that there had been a breach of this provision on account of the defects in the planning and conduct of the ambush operation and the lack of an effective investigation. 1. Arguments of those appearing before the Court (a) The Commission 70. The Commission, referring to its findings on the evidence (see paragraphs 24–45 above), concluded that it was not established on the material before it that the bullet which killed Havva Ergi had been fired by the security forces, though there were strong indications that it may have been. Nor was it established that the operation had not been a genuine ambush directed against the PKK approaching the village such that the firing at the village could be said to have been an intentional infliction of injury on its occupants (see paragraph 41 above). On the other hand, the Commission was not satisfied on the evidence that the ambush operation carried out close to the village of Kesentaş had been implemented with the requisite care for the lives of the civilian population. In addition, it found that the Turkish authorities had failed to carry out an adequate and effective investigation into the death of Havva Ergi. There had accordingly been a violation of Article 2 of the Convention. (b) The applicant 71. In the applicant’s principal submission, given that there was no evidence of any PKK presence in the vicinity of Kesentaş on the night of the operation, the security forces had, in violation of Article 2 of the Convention, opened fire without any lawful justification (see paragraphs 9-11 above). The intention had presumably been to punish the villagers for the fact that a Government “collaborator” in the village had been killed by the PKK (see paragraph 9 above). It was for the Government to substantiate their claim that the PKK had been present (see paragraph 16 above). Since the Government had failed to adduce such evidence, the applicant must be regarded as having proved his assertion beyond reasonable doubt. Such an approach had been followed by other human rights bodies faced with a similar problem, as