The state's highest court has ruled that it's unconstitutional for anyone under the age of 21 to be sentenced to life in prison with no possibility of parole.
State law before the ruling allowed anyone over 18 to be sentenced to life without parole if convicted of first degree murder.
The Supreme Judicial Court ruled that the scientific record supports that emerging adults have the same core neurological characteristics as juveniles.
The ruling is retroactive, so anyone convicted of murder committed between the ages of 18 and 20 will be able to apply for parole.