In X v. State of Bihar & Anr., the Supreme Court issued comprehensive guidelines for Juvenile Justice Boards while conducting preliminary assessments under Section 15 of the Juvenile Justice Act for children aged 16–18 accused of heinous offences. The Court held that Boards must independently evaluate four statutory factors—mental capacity, physical capacity, understanding of consequences, and the circumstances of the alleged offence—without conducting a mini-trial or determining guilt. Expert opinions are advisory and cannot be treated as conclusive. Equal importance must be given to the Social Investigation Report and Social Background Report. The Court emphasized reasoned orders, independent application of mind, protection of the presumption of innocence, and the reformative objective of juvenile justice.