Nebraska lawmakers are trying to set a new minimum prison sentence for convicted murderers who committed their crimes as juveniles.

Lawmakers began debate Monday on a sentencing bill, introduced in response to last year’s U.S. Supreme Court ruling that invalidated life-without-parole sentences for juveniles.

Sen. Brad Ashford, chairman of the Judiciary Committee, presented a bill amendment that would set a 30-year minimum sentence for Nebraska offenders. The proposal would also allow judges to consider potential mitigating factors in sentencing, including an offender’s age, maturity and participation in rehabilitation programs.

Sen. Scott Lautenbaugh of Omaha is proposing a minimum 60-year sentence. Lautenbaugh argues that a 30-year sentence would let inmates qualify for release in as few as 15 years, under current sentencing guidelines.