What is the test for admitting evidence of juvenile misconduct in determining the appropriate punishment for a criminal offence?

Hall v. Florida (2014) U.S. , 134 S.Ct. 1986, 188 L.Ed.2d 1007 affects this issue. It does not. That case, involving a Florida restriction on evidence admissible to show that a person has an intellectual disability, is even further afield from this question than the other cases defendant cites. The high court has never suggested that evidence of juvenile misconduct may not be admitted in deciding the proper punishment for crimes an adult commits.