In one, Graham v. Florida, the court decided 6-3 that life sentences without the possibility of parole for juveniles convicted of crimes less than murder was cruel and unusual punishment which violated the eighth amendment.
In the other, United States v. Comstock, a 7-2 court stated the Congress had the authority to allow continued confinement of some sex offenders who had completed their sentences, even though this power is not an enumerated (or delegated) power granted to Congress in Article One. It was argued on the basis of the necessary and proper clause, though the dissent wondered necessary and proper to do what?