Not many years ago courts ruling on the law of sentencing
and correctional treatment said or implied that a sentenced per
son had few if any rights and was at the mercy of the courts and
correctional administration. This image of the legal situation
has changed and is changing. Persons who are being sentenced
and even prisoners have many rights. Due process of law, both
substantive and procedural, applies to them, derived from con
stitutional and statutory provisions, as interpreted by the courts.
Presentence and probation statutes play a significant role in this
development.