In a 3-part format, data are presented regarding impact on population, length of stay, and sentences imposed, respectively. The first part examines factors for the trend of increasing prison population in Illinois, particularly increases in murder and Class X and 1 populations due to determine sentencing. The analysis indicates the impact of life, death, and sexually dangerous persons sentences on the population as well as the impact of the changing habitual offender, habitual child sex offender, and guilty but mentally ill population. The second part provides information on the time inmates stay in prison with focus on the slow pace of releasing inmates under indeterminate sentencing and abolition of the forced release and misdemeanor admission policies. The third part provides data for sentencing patterns since 1978 including determinate and indeterminate, life, death, and sexually dangerous person sentences. In addition the number of extended and shortened sentences are also reported by offenses, and median sentences for major offenses are listed by court and region. 45 tables