SJC Exchange Library

Sentencing enhancements have been an increasingly important part of criminal sentencing in California for the last 40 years. During the “tough on crime” era of the 1980s and 90s, enhancement statutes such as Three Strikes were enacted that imposed what some saw as severe penalties for even relatively minor crimes. In recent years, enhancements have been regarded with increasing skepticism as mass incarceration and its attendant costs—both financial and social—have come under scrutiny. Still, little research has been conducted to help understand how enhancements contribute to time served in jail and prison.

Here we analyze nearly 8,000 felony cases that went to sentencing in San Francisco from 2005 to 2017. In aggregate, we find that enhancements accounted for about 1 out of every 4 years served in jail and prison. Only about 13% of cases were enhanced, but among enhanced cases, the enhancements more than doubled the base term. About half the time served for enhancements was triggered by prior convictions—time that was almost exclusively driven by two enhancements, “Prop. 8 Priors” and Three Strikes. The other half was due to enhancements for an individual’s conduct during the offense, particularly the “10-20-life” gun enhancement. While it is difficult to fully anticipate the effect of policy changes, these results suggest that one could substantially reduce incarceration by focusing on a small number of enhancements.