The next four chapters consider how the criminal justice system’s structural limitations intersect with individuals’ subjective lack of capability to create risk. This chapter examines how a defendant’s subjective lack of capability—experience through cognitive and linguistic absence—can exclude them from meaningful participation in the criminal justice process. Despite formal safeguards, the justice system often operates on assumptions of competence that overlook the significant barriers faced by individuals who cannot understand, process, or communicate within legal contexts. The chapter explores how language deficits, cultural misunderstandings, and cognitive disabilities undermine defendants’ rights, sometimes leading to false confessions or pleas, ineffective legal representation, and miscarriages of justice. The chapter further explores the fallibility of demeanour assessments and how misinterpretations can undermine credibility, especially for defendants from diverse linguistic and cultural backgrounds or with communication impairments. By analysing case studies like Gibson and Murray v Feast, alongside legal principles like the right to silence and the Anunga Rules, this book underscores the essential role of judicial gatekeeping in ensuring a fair trial for all, particularly vulnerable individuals. Ultimately, the chapter argues that access to justice demands not only procedural fairness but an active recognition of the capabilities required to engage with the system—and the profound consequences when those capabilities are lacking or ignored.