A Christchurch man who hung out with gangs for six years said he did it for first-hand research.
Jarrod Gilbert spent time with gangs and made key relationships in order to understand them for his 2013 book Patched: The History of Gangs in New Zealand.
The book gained him numerous awards but it came at a risk for Gilbert.
Gilbert's newest book, which is yet to be released, is about murder with a focus on child homicide.
He said children were the most vulnerable members of the household.
"We beat kids to death," he said.
"The explanation for that is kids that age obviously have no network. They can't run away. They can't ask for help. They are being killed by the people who are meant to be caring for them."
Gilbert was hopeful his new book would be published within two years.
Listen to the interview with Gilbert below.