"64. The procedural obligation requires a state, of its own motion, to carry out an investigation into a death that has the following features - (i) it must have a sufficient element of public scrutiny of the investigation or its results. (ii) it must be conducted by a tribunal that are independent of the state agents who may bear some responsibility for the death. (iii) the relatives of the deceased must be able to play an appropriate part in it. (iv) it must be prompt and effective. That means it must perform its essential purposes. These are to secure the effective implementation of the domestic laws which protect the right to life and to ensure the accountability of state agents or bodies for deaths occurring under their responsibility."