In the legal and mental health fields little is known about the therapeutic impact of courtroom psychology during criminal trials. The purpose of this research study was to investigate the inter-relating factors of law and psychology throughout criminal trials as experienced by lawyers and psychologists. Research questions explored the influence of courtroom psychology on criminal trial proceedings and challenges as experienced by both criminal trial attorneys in presenting mental health evidence, and by psychologists when testifying during criminal trials. Further exploration focused on the significance of courtroom psychology, and how lawyers and psychologists perceived courtroom psychology impacting justice for victims and influencing offender rehabilitation sentencing decisions. Procedural justice was the conceptual framework utilized in this investigation, and therapeutic jurisprudence was the theoretical base that guided this study. A qualitative-phenomenological research design was applied by interviewing 4 criminal law attorneys and 4 clinical forensic psychologists. Four themes emerged from the thematic analysis of the data collected: (a) an increase in the enhancement of psycho-legal services, (b) a need for additional education, (c) a desire to improve professional relationships through collaborative efforts, and (d) a demand for requiring advanced training. These results may serve as a foundation for professionals to provide ethically effective and relevant legal-therapeutic services for progressing courtroom psychology measures. Implications for positive social change from this research include recommendations to government, legal, and mental health system entities to consider generating and readjusting standards of practice that govern criminal trial proceedings.