Name:Dr. Zito
Alias:W. Morgan Sheppard
Psychopathic doctor who attempted to use a fellow mental institution inmate Eric Cross to exact revenge on Kate Murphy, the police officer who incarcerated him. He was foiled after Mac, who was working with the police testing drug bust equipment, got assigned to the case. He later escaped with the help of a unsuspecting psycologist, and again attempted revenge, this time at Mac for defeating him, using Pete, the doctor, and Murphy as bait.