Highly educated and a devoted father and husband, Dr Paul Wood's past isn't immediately obvious.
But his job is now devoted to that past.
Aged 18, as an unemployed high school drop out who was dependent on drugs, he was committing crimes to feed his habit.
While struggling with the death of his mother, Wood killed his 42-year-old drug dealer after he attempted to sexually assault him. Wood was convicted of murder and served 11 years in prison.
Another convicted killer, John Barlow — sentenced in 1995 for murdering Eugene and Gene Thomas — was among other prisoners who encouraged the teenager to educate himself behind bars.
Wood, now 42, became the first person in New Zealand's history to progress through undergraduate and masters degrees while in prison, completing his MA in psychology in 2005 with Massey University. He was also the first person to begin a doctorate while incarcerated.
He was released from prison in 2006 and in 2011 graduated with a PhD in differential psychology. Barlow attended his graduation.
Read: From murder to masters degree: Paul Wood's rise to highly educated, loving family man
Wood now lives in Wellington with his wife Mary-Ann — who he met after his release at a mutual friend's Christmas gathering — and their sons Braxton, 4, and Gordy, 1.
He works as a motivational speaker and workshop facilitator for companies and individuals. He's a patron for START Taranaki, which specialises in turning around the lives of at-risk young men, and he regularly visits prisons to talk about his past.
His wife is completing her own masters degree in sport and exercise science.
In an extract from his new book, How to Escape From Prison, Wood tells how he turned his life around.