Whittal joined the Commission on Human Rights and Administrative Justice in 1994. His first position in the organisation was as the Upper East Regional Director. He served as the Director for the Legal and Investigations Department between 2008 and 2012. He was promoted Deputy Commissioner in charge of the same department from 2012, his last position before becoming the Commissioner. He was appointed the Commissioner in December 2016 by President John Mahama. This was shortly after the December 2016 general election which Mahama lost. The New Patriotic Party which had won the election and was due to take office under Nana Akufo-Addo a few weeks later expressed disapproval at his appointment.