Many believed TSLs would lower crime rates. Proponents of TSLs argued the policy would deter and incapacitate violent felons and lower crime rates by increasing the certainty and severity of punishment through the reduction of judicial sentencing discretion. (Kovandzic, Sloan, &Vieraitis, 2004).
Wanting to evaluate whether TSLs deter crime, The Justice Policy Institute (1999) collected data from California counties to measure the rates of sentencing. Researchers found that the highest sentencing counties apply TSLs at rates three to twelve times higher than the lowest sentencing counties. However, they also discovered the highest sentencing rates did not have a significant impact on crime. In fact, some counties experienced a higher rate in