They're spending over half a million dollars a year to house prisoners[0]. The resources are there but they're not using them for rehabilitation.
[0] https://comptroller.nyc.gov/newsroom/comptroller-stringer-co...
[0] https://comptroller.nyc.gov/newsroom/comptroller-stringer-co...
To illustrate this: If you lived in a 3-bedroom apartment, how would you personally feel about taking on the task of housing someone off of craigslist in exchange for them promising to pay 1/2 of your rent?
How would you feel about doing that for someone recently convicted of larceny or arson or selling fentanyl?