This paper explores the connection between law and social change by looking at Insite, North America’s first legal supervised injection site, as a case study. The paper focuses on how the Canadian Supreme Court was primed to grant legal status to the site. By examining the deep, grassroots, addict-led movement that set the foundation for the site to exist, the paper looks at how local movements coupled with evidence-based statistics can help inform judges in making decisions that affect social change. The paper looks closely at how advocates drew on both the social movement and the law in defending the legality of Insite.