Widespread and intense non-state actor violence in the Americas poses critical challenges for the international legal framework and the protection of human rights. Human Rights in Practice undertook a consultancy study for CEJIL on the legal challenges related to violence by non-state actors in the Americas. The report highlights trends and developments in law and practice, challenges and opportunities, in relation to state responsibility for non state actors, and non state actor responsibility for human rights violations. It is hoped to develop the study for publication.