Traditionally, forensic mental health services have focused on the assessment and treatment of offenders with serious mental disorders. In recent years, there has been growing recognition that forensic clinicians have an important role to play for those offenders who engage in criminal acts driven by psychological or/and social problems, which may, or may not, occur in conjunction with a major mental disorder. This is especially true for specific offenses such as stalking and threatening. This article describes the innovation of the problem behavior model. This model uses a reductionist approach and the nexus between psychiatry and psychology to address the complex phenomena associated with specific problem behaviors that often culminate in offenses. The model is illustrated by describing the development of specialist clinics for the problem behaviors of stalking and threatening.