In the Supreme Court case of [Roper vs. Simmons] (2005), the Supreme Court overturned the imposition of the death penalty for juveniles. Because of the ruling, every State had to convert those juveniles in their state sentenced to death to life in prison. Why did the states have to conform to the ruling instead of the ruling applying to only those juveniles sentenced after the 2005 decision? In other words, why did the ruling apply retroactively?