Truth in sentencing laws are enacted to reduce the possibility of early release from incarceration. It requires offenders to serve a substantial portion of the prison sentence imposed by the court before being eligible for release. Previous policies which reduced the amount of time an offender served on a sentence, such as goodtime, earned-time and parole board release, are restricted or eliminated under truth-in-sentencing laws.The definition of truth in sentencing laws and amount of time required to be served are primarily governed by state laws, which vary by state.
Although the time usually varies from 50% to 100% of the prison sentences, in most truth-in-sentencing states offenders are required to serve 85% of the prison sentence. This is influenced by the opportunity to receive federal funding for prisons. The U.S. Congress has authorized incentive grants to build or expand correctional facilities through the Violent Offender Incarceration and Truth-in-Sentencing Incentive Grants Program in the 1994 Crime Act (Pub.L. No. 103-322, 108 Stat. 1796 (1994)). To qualify for the truth-in-sentencing grants, states must require persons convicted of a Part 1 violent crime to serve not less than 85% of the prison sentence. Along with other exceptions, states may qualify by demonstrating that the average time served in prison is not less than 85% of the sentence.