Our text defines selective incapacitation “Incapacitating high-risk offenders believed to pose substantial probability of additional crime, usually through imprisonment.”(Allen,H Ed. 14) This concept can be effective because it enforces the imprisonment of criminals that have committed violent crimes and alterative punishments for criminals with minor crimes.Selective incapacitation also seeks to protect society and save limited corrections resources by incarcerating only those offenders who pose the greatest threat to society. Threat is equated with quality and quantity of offenders’ offenses and likelihood of re-offending. This will open more space in prisons and prevent criminals that have committed heinous crimes to be released on probation or parole due to overcrowding of prisons. ”Greenwood argued that prison overcrowding and the scarcity of beds in prisons require a policy of sending only repetitive or violent offenders to prison: he especially recommended prison for those who commit armed robbery. He believed selective incapacitation would thus result in better uses of correctional resources and effective crime prevention.”(Allen, H. Ed. 14)