In The Iceman: Confessions of a Mafia Hitman, the chilling interviews Dr. Dietz conducted with Richard Kuklinski demonstrate a man with significant psychological damage, which led him to kill over two hundred people over the course of his life, through various and sadistic means. If one were to look at his condition from a Freudian perspective, it is easy to see that he has many psychosexual issues related to his mother. Growing up in a violent environment, with his mother beating him often and violently, Kuklinski learned that violence was the way to get what you wanted, leaving him in the latent period of psychosexual development. Here, he suppressed his libido and redirected it into violence, using it as a means of transference. He was reacting against his mother and those who tormented him as a child, on his victims; this is why he performed many of his murders so inventively and slowly. His psychopathy and antisocial behavior came from his inability to relate to others, and his own anxieties about belonging and being part of society.
Kuklinski's affiliation with the mob also relates to his need to belong; not feeling as though he belonged in polite society, he managed to fall in with a group that cared as little about law and society as he did. Outwardly, however, he seemed to be able to repress those impulses, as evidenced by the courteous and loving relationship he had with his wife at the time. Kuklinski's repressed anger is visible in the interviews; his abuses early in life had a clear effect on him, and this is what causes his psychopathy (in addition to the Oedipal anxieties regarding his abusive mother, as Freud would likely note - he has psychosexual issues about intimacy, power and control that stem from his mother's abuse of him in his youth) (Ewen 2003, p. 11).
If I were to have a therapeutic intervention with Kuklinski, I would attempt to, first and foremost, get him to develop remorse and guilt about the things he had done. One of the earliest things he states in the documentary is that he feels no guilt for the people he has killed; this shows a remarkable lack of empathy on his part. I would like to use empathy-building activities that are often used for this purpose in children's therapy, but obviously adapted for Kuklinski. I would have him read monologues out loud that describe someone's suffering from their perspective, and ask him to describe the feelings of that person in the situation, and the reasons for that feeling. I would also ask him what reasons that person had for not getting help for their problem, and what someone could do to help in a particular situation. While achieving an effect for someone like Kuklinski might be difficult, forcing him to go through the thought processes of someone who is victimized might lower that alienation effect and see these people more as people.
I would also use visual aids to help build empathy; starting with pictures of upset children, to animals, then perhaps to pictures of his victims, to at least gauge his ability to get an emotional response. I would also ask about his mother, and how he felt about his relationship to her, particularly the violence she inflicted upon him.
Looking through the interviews, it seems that Dr. Dietz has a precise amount of control over the situation - his calm and ordered questions allow us to learn as much as possible about Kuklinski, and also manages to corner the man a few times. It is here that we learn (and see) just how angry Kuklinski gets when he does not have control over the situation, as he gets clearly anxious once he is trapped in an emotion or moment. Dietz's diagnosis of Kuklinski as anti-social and paranoid is also quite accurate and telling, as Kuklinski is constantly afraid of betrayal, which he experienced in his childhood quite frequently between his mother and peers, and so he keeps society at a distance. Dietz's approach is about as good as you could get with Kuklinski, a man who keeps his emotions very close to the vest.
Kuklinski is described as "nothing more than a predator on other human beings" in the documentary (Dietz, 2001). However, I believe that there is more to him than that, despite his outward remorse. It becomes clear in the documentary that Kuklinski's amorality and aloofness toward the lives of others is a desperate defense mechanism to prevent himself from getting hurt. Near the end, he says that the one friend who got him in his position is "the one friend I didn't kill"; this shows how distrustful he was of having anyone close to him. Killing gave him the power and control he needed to have over his fellow human beings, and so this does give him a very sad motivation for these killings - one which Kuklinski represses and denies.
References
Dietz, P. (1991). The Iceman: Confessions of a Mafia Hitman. HBO Films.
Ewen. R.B. (2003). An introduction to theories of personality (6th ed.). Psychology Press.