From his early days as a police officer Luke became a union activist serving as a branch official, conference delegate and Executive member. In 2006 he became treasurer. During his 7 years on the Executive, Luke championed many causes including research into, and the trialling of, gel belts and mental health reform. For his contribution to workplace safety he received an award from Unions NSW in 2003 and in 2005 from the NSW Government. He is also remembered for establishing a Campaigns Fund for fighting future campaigns. Luke joined the NSW Police in November 1982 and retired in August 2009 with the rank of sergeant.