Research Report No. 4: Less-Lethal Arms & Munitions Documented in Ferguson, Missouri examines impact and riot control agent (RCA) munitions employed by security forces during the 2014 riots in Ferguson. Authored by chemical weapons specialist Peter White and ARES Associate Researcher Stephen Semler, the report also provides a brief overview of the development history and employment methods of some common less-lethal munitions. These munitions are commonly employed by police and security force in their efforts to counter violent actions associated with civil unrest, and are commonplace in many countries.