Chief Justice of Tanzania (2010 -2017). In 2023, he served as Chairperson in the Presidential Commission on the Reform of the Criminal Justice System and Institutions in Tanzania. He was appointed (since 2017) by UN Secretary-Generals, as Eminent Person and charged with the investigation related to the tragic death of the second UN Secretary-General, Dag Hammarskjöld and other members, in 1961. Othman is currently Chairperson of the UN Human Rights Council’s International Independent Fact-Finding Mission on Sudan.

He previously held positions as Prosecutor General, Timor Leste (2000-2001) and Chief of Prosecutions, International Criminal Tribunal for Rwanda (ICTR) (1998-2000).