Group Captain Henderson joined the RAAF in July 1990 while studying law at Monash University and commenced his first full-time posting in April 1993. Recent postings include being a Senior Prosecutor at the Office of the Director of Military Prosecutions and a 2-year loan to the United States armed forces as a Law of Armed Conflict, International and Maritime Law advisor at United States Central Command. He is currently the Director Military Law Centre and Deputy Director Asia-Pacific Centre for Military Law, where he is responsible for the legal training of Australian military lawyers and commanders, and delivering legal training to regional militaries. He has deployed to East Timor (1999), Afghanistan (2002), and to the Middle East (2003) where he was the senior Australian legal officer in the Combined Air Operations Centre.
He has published a number of journal articles and book chapters, and is the author of The Contemporary Law of Targeting: Military Objectives, Proportionality and Precautions in Attack under Additional Protocol I (Martinus Nijhoff, 2009).
He was made a Member of the Order of Australia (Military Division) in 2011 ‘for exceptional service in the field of military law’.