Alabama v Miller Case

In the essay assignment the case that I was assigned a case Miller v Alabama. My case was based on a 14 year old boy Evan Miller who killed his neighbor along with one of his friends by beating him up with a baseball bat, and then burning down his trailer while the guy was still alive inside as a result, the guy ended up dying. After all of this, they sentenced the 14 year old to a term of life in prison without the possibility of parole. Of course, Miller had an appeal and he argued that this was cruel and unusual punishment for someone that was his age and that it violated his Eight amendment rights. Throughout the whole case, the "big question" was on deciding if the sentencing a young boy to a life sentence in prison was cruel and unusual punishment for someone his age". While doing the paper another case that had caught my eye which was kind of similar was a case with another 14 year old boy by the name of Kentrell Jackson who along with his two 14 year old friends were going to rob a local movie store and one of his friends ended up shooting the store clerk which then they fled the scene. This young 14 year old was also sentenced to a life sentence in prison. But the one thing that separated this from the Miller v Alabama case was they he was not really the one who killed the store clerk, his friend did, so how could he serve such a sentence. The reason why I think he served such a sentence was because he did sort of just left the guy there to die.