[2] He served as Families Commissioner between 2008 and 2011, having previously been the national director of Prison Fellowship New Zealand.

[3] Workman has been a long-time advocate of prisoners' rights and for reform in the criminal justice system: he founded the Robson Hanan Trust, which is responsible for the Rethinking Crime and Punishment strategy, and was also the founder of JustSpeak, a youth network seeking changes in the criminal justice system, in 2011.

[3] From 2012 to 2013, he was a member of board of the Prisoners Aid and Rehabilitation Trust, and in 2013 he was appointed as an adjunct research fellow at Victoria University of Wellington's Institute of Criminology.

[3] In March 2021, he was appointed chair of an independent research panel investigating unconscious bias in New Zealand Police.

[6] In the 2019 New Year Honours, Workman was appointed a Knight Companion of the New Zealand Order of Merit, for services to prisoner welfare and the justice sector.