In 2016, the United Nations General Assembly adopted a resolution establishing the International, Impartial and Independent Mechanism (IIIM) to assist in the investigation and prosecution of the most serious crimes committed in Syria since March 2011. In this interview IIIM Head, Catherine Marchi-Uhel, explains how the Mechanism collects evidence in Syria, and how this evidence is being used in national proceedings in various countries such as Germany and Sweden. She also talks about the importance of maintaining the chain of custody, as well as processes put into place to ensure the reliability and authenticity of the evidence collected. The IIIM also draws up analytical reports for future trials at international or internationalised courts, such as the ICC or special tribunals.