A rehabilitation policy within criminology, is one intending to reform criminals rather than punish them and/or segregate them from the greater community.
History
Some early eighteenth and twentieth century prisons were proponents of rehabilitative policies. "Early American prisons, such as those at Auburn, Ossining, and Pittsburgh during the 1820s, implemented rehabilitative principles. These early programs isolated convicts in order to remove them from the temptations that had driven them to crime and to provide each inmate with time to listen to her conscience and reflect on her deeds...This belief that all convicts would return to their inherently good natures when removed from the corrupting influences of society gave way to more aggressive forms of treatment informed by the rise of social scientific studies into criminal behavior. Research in psychology, criminology, and sociology provided reformers with a deeper understanding of deviance and sharper tools with which to treat it. Rehabilitation became a science of reeducating the criminal with the values, attitudes, and skills necessary to live lawfully." The philosophy of rehabilitation is that "not the offense but the character and reformability of the offender should determine his treatment."
"Then, in the early 1970s, rehabilitation suffered a precipitous reversal of fortune. The larger disruptions in American society in this era prompted a general critique of the “state run” criminal justice system. Rehabilitation was blamed by liberals for allowing the state to act coercively against offenders, and was blamed by conservatives for allowing the state to act leniently toward offenders. In this context, the death knell of rehabilitation was seemingly sounded by Robert Martinson’s (1974b) influential 'nothing works' essay, which reported that few treatment programs reduced recidivism. This review of evaluation studies gave legitimacy to the antitreatment sentiments of the day; it ostensibly “proved” what everyone 'already knew': Rehabilitation did not work."
Deterrence (legal) and incapacitation ruled over the criminal justice system until the 90's where an unmanageable increase of the prisoner population created gaps where the benefits of rehabilitative policy could be discussed. "The increase of the prisoner population in the United States has resulted in shifting opinions on punishment vs. rehabilitation policies.
Policies
Indeterminate sentencing
Indeterminate sentences are sentences where a judge indicates a minimum and maximum time for an offender to be imprisoned. The prisoner may be released anytime between the established minimum and maximum time. Indeterminate sentencing expanded discretion into the prison system so that prisoner rehabilitation could be analysed on the individual level. Indeterminate sentencing is personalized opposed to determinate sentencing which is standardized. "Advocates of determinate sentencing have argued that inmates support determinate sentencing because they strongly resent uncertainty of time to be served and sentencing inequity under indeterminate sentencing." Because indeterminate sentencing expands discretion, offenders with similar crimes may serve vastly different prison times. Indeterminate sentencing exchanges equity of law for personalization of rehabilitation.