There are 24,000 deaths from suicide annually in the United States and 7,000 from homicide. In addition there are several times as many unsuccessful suicide attempts and attempted homicides, mayhems, and serious assaults and batteries. It is safe to say that a large portion of these involve persons with psychiatric disorders and thus fall under medical jurisdiction.
Some of these individuals are overtly psychotic: deluded and hallucinated, or uncontrollably depressed, or assailed by intolerable anxiety, guilt, or hostile feelings. More are acutely neurotic, and their acts may be seen as manipulative gestures, or cries for help, or acting-out maneuvers. A large portion have disordered personalities and faulty character structures, often with alcoholism, narcotic addiction, sexual psychopathy, passive-aggressive disturbance, or emotional immaturity, instability, or inadequacy. Frequent accompaniments are adolescent turmoil, marital discord, school or work problems, chronic or terminal illness, or geriatric disease. Thus the physician has usually been consulted before
Solomon P. The Burden of Responsibility in Suicide and Homicide. JAMA. 1967;199(5):321-324. doi:10.1001/jama.1967.03120050063013