Dr. Ng served in the Hong Kong Police for over three decades until he retired in 2012 as an Assistant Commissioner of Police. He spent most of his police career in criminal investigations duties. In his early years, he studied Sociology in the Chinese University of Hong Kong and graduated with a Bachelor of Social Science degree. Later, he obtained a Master of Criminology from the University of Hong Kong, and a PhD in Sociology from the Chinese University of Hong Kong. Since retirement, Dr. Ng began to teach for several years in the Chinese University and the University of Hong Kong, both in post-graduate programme. At the same time, he devoted himself to a number of community services.