The Capstone Exercise 2020│2022 was a two-part simulation exercise including a table top exercise (TTX) and a field exercise conducted by the Robert Koch Institute (RKI) to strengthen the United Nations Secretary-General’s Mechanism for the Investigation of Alleged Use of Chemical, Biological or Toxin Weapons (UNSGM). This report summarizes the organization and outcomes of the Capstone Exercise based on the evaluation which was conducted with the RKI as exercise managers and with the support of the Swedish Defence Research Agency (FOI) for scenario development and exercise evaluation. The report was developed collectively by the RKI, the FOI and a number of evaluating observers.