The slain youth, 19-year-old Win Rozario, was suffering from mental health issues, according to his family
Nurul Kadir, additional secretary to the Ministry of Environment and Forests Climate Change, will replace him in the Department of Environment.
Sultan takes over the office of chairman of the capital development authority from Abdur Rahman, who ran his term on May 14.
Sultan had previously served as an additional secretary to the Environment, Forest and Climate Change Ministry.