Violent crime
Violent crime was not responsible for the quadrupling of the incarcerated population in the United States from 1980 to 2003. Violent crime rates had been relatively constant or declining over those decades. The prison population was increased primarily by public policy changes causing more prison sentences and lengthening time served, for example through mandatory minimum sentencing, "three strikes" laws, and reductions in the availability of parole or early release. 49% of sentenced state inmates were held for violent offenses.