In recognizing the new principle, Abella J reviewed the long tradition of the Canadian justice system treating youth and adult accused differently. She reviewed the Juvenile Delinquents Act and the Young Offenders Act, which taken together with the YCJA demonstrated a century old practice of distinctive treatment for juvenile offenders relative to similarly situated adults. She noted that the motivation for enacting said laws was rooted in the belief that youth were less morally blameworthy, and more in need of an approach centred on welfare and rehabilitation. She also found further support for this notion in Convention on the Rights of the Child, of which Canada was a signatory. She also noted it was widely acknowledged that age plays a role in decision making capacity and moral development, and Canadian courts had long taken notice of that fact. Overall, Abella held that there was widespread societal consensus that the presumption of diminished moral blameworthiness was fundamental to the fair operation of the legal system. She also found the principle to yield a manageable legal standard.
