|“||I don't think it's possible for a person to understand themselves.||„|
|~ John Tagman's most famous line|
John Tagman is the main antagonist of the Law & Order: Criminal Intent episode "Want". He is a serial killer who turns his victims into mindless and subservient "zombies". He is based on serial killer Jeffrey Dahmer.
He was portrayed by Neil Patrick Harris, who also played Foy in A Million Ways To Die in the West, Chester Creb in American Horror Story: Freak Show, Dr. Horrible in Dr. Horrible's Sing-a-Long Blog, and Dr. Blowhole in The Penguins of Madagascar.
Tagman is a shy, quiet man who lives a solitary existence, with no friends or girlfriend. He has very poor social skills, so the love and companionship he desires constantly eludes him. He has a rich fantasy life, however, which grows darker and more violent as his loneliness grows deeper; he begins fantasizing about killing a woman so he can "possess" her forever.
His first victim is a stripper whom he drugs and strangles; he then removes her calf muscle and eats it so he can feel that she is a part of him. He injects acid into his second victim's brain; she lives, but is left so badly brain damaged that she does not even know her own name.
Detective Robert Goren comes to suspect Tagman after seeing him on the strip club's security camera talking to the first victim. He and his partner Alexandra Eames visit Tagman's workplace, a chocolate factory, and notices Tagman's extreme shyness around Eames. They have Tagman detained so they can search his apartment, where they find several bottles of alcohol, cups of ice and a drill bit. They also find the second victim's calf muscle in a bodega across the street.
After Tagman is released, Goren takes him to lunch to "apologize", and profiles him; he sees that Tagman is a depressed, profoundly lonely alcoholic, and theorizes that he kills to fulfill his fantasy of a submissive and eternally beautiful partner who will never judge or leave him. He also believes that Tagman feels remorse for his crimes, and wants to stop killing. He recommends to his skeptical colleagues that Tagman should be spared the death penalty and put in prison for life.
Goren and Eames arrest Tagman for kidnapping and assault, and trick him into revealing information that the District Attorney's office can use to convict and execute him. Goren has a moment of conscience, however, and tries to save Tagman's life by getting him to confess. He tells Tagman that he is sick, not evil, and that the only way he can be free of his pathology is to take responsibility for what he did. Tagman bursts into tears and confesses, which makes him ineligible for the death penalty. He is sent to prison for life, but is soon after beaten to death by another inmate.