Many people convicted of criminal offenses have a complex history of trauma that is overshadowed by the harm caused by their crimes. Although these truths do not excuse their criminal behaviors, it is important to understand and respond to trauma as one of the numerous and complex factors that contribute to criminality. Efforts to reduce crime and prevent future offending can be strengthened through trauma-informed policies and interventions. This chapter provides insight on the importance of trauma-informed care (TIC) in the criminal justice system by (1) discussing risk factors for criminality within the context of childhood adversity and adult trauma; cultural, historical, intergenerational, and systemic racism; and the trauma of poverty; (2) conceptualizing the impact of trauma on development of behavioral problems and mental health disorders; and (3) defining and describing trauma-informed care for practitioners in the criminal justice system. TIC uses principles of safety, trust, empowerment, choice, and collaboration to enhance engagement, build self-regulation and resilience skills, and avoid retraumatization of criminal justice clients. This chapter concludes with useful questions that professionals and organizations should consider when implementing trauma-informed care in their practice.