Life Imprisonment of Juveniles

Life imprisonment for juveniles is an issue in the world today. Juvenile are getting sent to jail for their whole lives.Children as young as 14 years old are getting sentenced to life in prison. A lot of people don't think that it is right that children are getting their whole lives taken away for something that they might not have even intended to do. Some people say that children under the age of 18's brain's haven't completely developed. Another
thing is that at the age of 18 the brain still isn't completely developed. Juveniles are being tried as adult in parts of the united states. It is cruel and unusual punishment. An example of this was in a prison, an inmate was beaten by the guards even though he was wearing hand cuffs. Life imprisonment is cruel and unusual punishment.

How many states have convicted juveniles to like imprisonment?
How many children have been sentenced to life in prison?
What is considered a cruel and unusual punishment?