He was the longest serving Inspector General in Bangladesh Police's history.

[5] Khandker joined the police department in 1984 as a member of the Bangladesh Civil Service cadre of the 1982 batch.

He served as director general of Rapid Action Battalion during February 2007 to August 2010.

During his tenure as the IGP, Bangladesh Police received the Independence Day Award.

[8][1] Khandker has charges against him in International Criminal Court (ICC) for crimes against humanity.