This is a simple, obvious premise, but capitalists don’t seem to get it (the book The Enterprise of Law, for instance, which is really good at pinpointing the fundamental issues with the “justice system” but proposes the absurd solution of privatizing everything): when prisons are for-profit, prisoners become a commodity. This is what happened in Louisiana, which now has the highest rate of imprisonment in the world.
The motivation is money. Most prisoners in Louisiana are in for-profit prisons. The state spends $663 million a year on imprisonment; $182 million of that goes to for-profit correctional companies or contracted local sheriffs. Many small towns depend on the prisons to fund their law enforcement.