MO SB280

Eliminates mandatory life without parole for offenders under 18 convicted of first degree murder, in response to the U.S. Supreme Court's Miller v. Alabama decision declaring such sentences unconstitutional

Establishes new sentencing ranges for juvenile first degree murder: 14-30 years or life for offenders aged 16-17; 12-30 years or life for offenders under 16

Requires courts and juries to consider specific factors when sentencing juveniles, including the defendant's age, mental capacity, maturity, criminal sophistication, prior history, and victim impact statements

Creates a petition process allowing individuals currently serving mandatory life without parole for offenses committed as juveniles to request resentencing under the new provisions

Contains an emergency clause making the juvenile sentencing provisions effective immediately upon passage, with other definitional updates to Section 556.061 taking effect January 1, 2017