where the gang began
In recent years the Royal Commission of Inquiry into Abuse in Care has probed these state and faith-based set-ups.
But there is a sense gang members have been reluctant to engage. That is something the Waikato chapter of the Mongrel Mob is out to change.
On Friday evening Paul Zentveld, a former patient of the child and adolescent unit at the notorious Lake Alice psychiatric hospital, spoke to a room full of Mongrel Mob members and their families.
He told them about his experiences there in the 1970s, when he was drugged and given painful electric shocks as punishment.
Zentveld's story began a weekend hui at Poihākena Marae in Raglan about trauma. It is run by the Waikato Mongrel Mob Kingdom in what is thought to be a New Zealand first.