Forensic psychiatry is a field that encompasses everything at the interface of mental health and the law. It is a sub-specialty of the medical discipline of psychiatry, which requires additional training and credentialing beyond what is required to become a clinical psychiatrist. A forensic psychiatrist is a physician who has expertise about mental health and the law and who can serve in a variety of treatment, consulting, expert witness, or political roles. In comparison, a forensic psychologist is not a physician. Criminal psychiatry and forensic mental health services go hand in hand when it comes to forensic psychiatry.