In 1998 Usman was a student activist from Trisakti University where four students were shot dead, this incident triggering a nationwide protest that toppled the Suharto regime. In 1999 he joined the police and the military ballistic team to identify bullets that killed his fellow students through laboratory work in Montreal, Canada.
He became the coordinator of KontraS, the Commission for Missing Persons and Victims of Violence. In 2004 Usman was appointed a member of the Presidential Fact-Finding Team that investigated the 2004 murder of prominent human rights defender Munir Said Thalib. Usman went on to a fellowship at Nottingham University in 2009. He served as an expert adviser to the International Center for Transitional Justice, Jakarta office, from 2010 until 2012. In 2011 Usman was appointed to the Presidential Working Unit for the Supervision and Management of Development, where he reviewed the policy on Indonesia’s Human Rights Nation Plan of Action of 2011–2014. In 2012 Usman co-founded Public Virtue Institute and the Indonesian Branch of Change.org, the world’s largest online petition platform.
He has been a visiting scholar at University of Columbia (2003) and held a fellowship at Nottingham University (2009).