Uncle Basil (Mulla) Sumner started the motorcycle club Black Death to hold a spotlight to Aboriginal deaths in custody.
"People think (the group) is an evil, sinister type of thing, but it's not, this is for black deaths in custody," he told AAP.
"The colours I put on, I wanted right in the face of the government and the police so they could see it loud and clear."
It's an issue close to the Ngarrindjeri elder's heart and forms part of his story told through a new documentary, 'There I was, here I am'.
He features along with Kaurna-Narungga woman Aunty Frances Chantrill and Ngarrindjeri-Narungga man Uncle Craig Dodd,
As a young person, Uncle Mulla was in and out of prison, experiencing homelessness and struggling with addiction.
"I remember when I was in jail, when I think about it, it really was all Aboriginal people in jail, just for minor things" he said.
"When public drunkenness was a crime in South Australia, that's what we'd get picked up for.
"Before 1967 it was illegal for Aboriginal people to even have a bottle in their house, or carrying a bottle on them... it was a crime to be in possession of alcohol and I lived through those days."
Uncle Mulla was born at Raukken, known then as Point McLeay Mission, about 80 kilometres southeast of Adelaide.
Now 75, reflecting on his life, Uncle Mulla said the roots of many of his struggles grew from the policy of assimilation, which attempted to erase the identity and presence of Aboriginal people.
"To get to this age, I think I'm pretty lucky," he said.
"Before all of this, I was heavily involved in drugs and alcohol, finished up a lot in jails.
"I blame it all on the assimilation, it disintegrated my family with us kids finishing up in (children's) homes."
Uncle Mulla has now been sober for decades, saying he started "drying out" in 1978.
A passionate advocate for his people's health and wellbeing, Uncle Mulla was the chair of the state's biggest Aboriginal Health Organisation Nunkawarrin Yunti for 20 years, and at the head of the Aboriginal Sobriety Group for 30.
Uncle Mulla said it was important to him to get his story, his culture and language out there for everyone to see.
"It's important we get our word out there," he said.
"To share the knowledge that we have and to show that we've got our own culture and we are different."
The documentary, 'There I was, here I am', was launched in front of 300 elders and carers in Adelaide.
It was developed by Aboriginal Community Services and funded by the National Indigenous Australians Agency.
The aim is to use the documentary as a starting point for a digital record-keeping project, preserving elders' histories through oral storytelling.
