<p>Doubts about an offender’s criminal competence typically lead courts to mandate a psychiatric evaluation to determine whether a mental disorder impaired the defendant’s capacity to understand their actions or to control their will. While criminal law relies on folk-psychological concepts to determine responsibility, psychiatry examines behavior through cognitive and neurobiological frameworks. This contrast raises the question of how the folk-psychological explanations central to legal reasoning relate to, and can be integrated with, the neurobiological and mechanistic explanations employed in psychiatric assessment. The issue exemplifies the broader philosophical problem known as the interface problem, which concerns how to understand the relationship between personal- and subpersonal-levels of explanation and the constructs associated with them. The paper considers three solutions—autonomism, functionalism, and the co-evolutionary view—and argues that the co-evolutionary view provides the most suitable framework for forensic psychiatry.</p>