That’s an incredibly serious claim to make, do you have evidence to support your claims?
There's an explicit carve out in the 13th amendment's slavery prohibition for people convicted of crimes.
Many private prisons have contracts with states guaranteeing them a quota of prisoners, on pain of monetary penalties. It becomes the job of police and courts to deliver that quota, regardless of behavior, because there is no money budgeted for penalties.
Everybody can be found guilty of something, if you want to.