When a delusional homeless woman is found strangled, Detectives Briscoe (Jerry Orbach) and Green (Jesse L. Martin) comb through the city's psych wards in search of a disruptive suspect (guest star Seth Barrish) but finally appeal to the man's agonizing parents (guest stars Joseph Hindy and Marcia Jean Kurtz) to help arrest him. However, Assistant D.A.s McCoy (Sam Waterston) and Carmichael (Angie Harmon) have a major handicap to overcome in prosecuting the accused when he suddenly refuses to take his antidepressant medicine - thereby rendering himself mentally incapable of standing trial for murder. S. Epatha Merkerson and Steven Hill also star.