They’re incarcerated primarily for offences against other indigenous people, ie domestic violence and assaults, and recidivist offending. Normalisation of violence, exposure to domestic violence, and substance abuse from an early age, are all major factors that contribute to this behaviour. (That’s not indigenous only of course - any child raised in the same sort of environment tends to have more experience with the justice system, it’s just indigenous households are over-represented in that description) Intergenerational trauma, distrust of police and other support agencies and cultural values regarding men’s and women’s business mean that it’s difficult to break that cycle. That’s where the effort and resources need to be focused, not protests about what happens when they enter custody. Diverting them in the first place is much more effective. But it’s hard, and people (governments) want quick and easy fixes, not multi-term solutions that won’t pay off before the next election.