S/2016/142 2/12 16-02054 Annex Letter of transmittal The Leadership Panel of the Organization for the Prohibition of Chemical Weapons-United Nations Joint Investigative Mechanism has the honour to transmit the Mechanism’s first report pursuant to Security Council resolution 2235 (2015) (see enclosure). The report provides an overview of the work of the Mechanism to date, the sources of information available to it and the methodological considerations behind its investigative strategy. It also outlines the steps it will undertake in the next phase, during which case-by-case investigation will be undertaken, with the aim of identifying to the greatest extent feasible individuals, entities, groups or Governments who were perpetrators, organize...