202. The duty.

Article 21 requires the state to have an effective judicial system enabling a thorough and effective investigation so that the cause of any death can be determined and those responsible made accountable2. It also imposes a procedural obligation to initiate an effective public investigation by an independent official body into any death occurring in circumstances in which it appears that one or other of the substantive obligations under Article 23 has been, or may have been, violated and it appears that agents of the state are, or may be, in some way implicated4. This procedural obligation does not arise