The United States is the only UN member that has not ratified the International Convention on the Rights of the Child, which prohibits sentencing under 18s to the death penalty or life imprisonment without parole. In states like Texas, 10 years olds can be sent to prison and children who commit a serious crime can be tried as adults and incarerated with them. It’s thought there are 10,000 Americans serving life sentences for crimes committed as a children.
