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Split Decisions in the Courtroom

The three legal faces of Dissociative Identity Disorder. used with permission
Source: used with permission

Dissociative identity disorder is a myth.

No, it’s a real mental illness.

No, it’s a metaphor for genuine pain and suffering, shaped by a therapist or the media.

What are we supposed to believe? The newly released movie, Split, with its unrealistic, sensationalized picture of Dissociative Identity Disorder, makes you wonder how much progress we’ve made in understanding — or at least portraying — mental illness. When it comes to DID, though, the controversy isn’t just on the silver screen; multiple perspectives have swirled around multiple personality disorder — now renamed dissociative identity disorder — ever since it appeared in the Diagnostic and Statistical Manual III in the 1980s.

When it comes to deciding what’s fake and what’s real, there is no place where the stakes are higher than in the courtroom; in 2016 alone, Dissociative Identity Disorder was offered as a defense in a child pornography case, by a mother accused of drowning her 2-year-old, and in the murder of a prostitute. Let’s take a look at the three “faces” of Dissociative Identity Disorder in the courtroom and the role a forensic psychologist plays in integrating them.

Billy Milligan: The “Successful” MPD

In 1978, 23-year-old Billy Milligan was arrested and charged with kidnapping, robbing, and raping three women close to Ohio State University. The first sign of Milligan's alter personalities appeared in the patrol car just after his arrest. The policeman who transferred him later remarked that he "couldn't tell.. what was going on, but it was like (he) was talking to different people at different times." One of the rape victims told an investigator that the rapist had a German accent, though Milligan was born and raised in the United States; another said he had been so nice that, in different circumstances, she might have considered dating him. During his trial, defense attorneys were able to show a documented history of “entering trances” and “wandering” dating back to junior high school and his self-reports of severe abuse by his stepfather, while not objectively documented, were backed up by his mother and siblings.

Mr. Milligan successfully pled not guilty by reason of insanity after two of his 10 alters, including a Yugoslavian con artist and a 19-year-old lesbian, came forward to take the blame. He was the first person to successfully use what was then called multiple personality disorder as an insanity defense. His case was also unique in that the verdict, rendered by a judge after the defendant waived the right to a jury trial, was uncontested by the prosecution. Mr. Milligan ultimately spent 11 years in a forensic psychiatric institution as was paroled after he was believed to be integrated.

Tom Bonney: A Case of Therapist-Induced Disorder?

Tom Bonney, on the other hand, certainly had mental health issues (mood swings, anger management problems) before he shot his 19-year-old daughter 27 times in November 1987. However, from all accounts, no one had ever used Mr. Bonney and multiple personality disorder in the same sentence until Dr. Paul Dell hypnotized the defendant and discovered 10 personalities, including an alter, Damien, who had allegedly committed the murder. The trauma that Dr. Dell cited as splintering Mr. Bonney’s personality was the death of his grandmother at age 10.

However, there were some problems with this diagnosis. First of all, after denying any involvement in his daughter’s death for weeks, Mr. Bonney had confessed to reporters shortly after his arrest; "It was just temporary insanity; somebody going over the edge," Bonney said. "I was depressed. My daughter was seeing a married man who had a baby."

Second, and particularly troublesome, Dr. Dell’s credibility as an unbiased evaluator of Mr. Bonney’s mental state was severely challenged on the witness stand. Dr. Dell reportedly had “diagnosed” Mr. Bonney before ever meeting him, based on newspaper reports of Mr. Bonney’s self-reported vague amnesia form some of the details of the crime and Dr. Dell’s firm belief that multiple personality disorder was not only under-diagnosed, but as natural a response to trauma as blood clotting is to a person who’s cut his finger while slicing a bagel. A self-described expert in multiple personality disorder, Dr. Dell contacted Mr. Bonney’s defense attorney and offered his services in evaluating the defendant for MPD.

On the witness stand, however, the clinical psychiatrist who had been instrumental involved in writing the official diagnosis of MPD for the APA’s manual on mental disorders, was highly critical of Dr. Dell’s diagnosis. Dr. Philip Coons testified that, after viewing 13 hours of videotaped interviews between Dr. Dell and Mr. Bonney, the psychologist asked leading questions, did not conduct a comprehensive interview before jumping into hypnosis, and improperly suggested that Mr. Bonney had other personalities and that, if he did, he might be committed to a hospital instead of a prison. Mr. Bonney was found guilty and sentenced to life in prison.

Ken Bianchi: Faking “Mad”

The moral of this story is that mental illness can be faked, experts can be fooled, and a forensic evaluator must operate differently than a clinician. Kenneth Bianchi, along with his cousin Angelo Bueno, was one half of the Hillside Strangler duo, who raped, tortured and murdered 10 Los Angeles women between October 1977 and February 1978; he later killed two women on his own in Washington State. After his arrest for the Washington murders, Bianchi provided a series of alibis that could not be substantiated; he also attempted to coerce his mother into typing up and mailing an anonymous confession (she refused) and convinced a female friend to lie and say he was with her at the time of the murders (she did but was not believed and later recanted).

In spite of this, Bianchi managed to convince four psychiatrists that it was his alter, “Steve Walker” who was really responsible for the murders; this occurred after he was allegedly hypnotized by one of the experts, who then requested to speak to “another part of Ken.”

The prosecution hired Dr. Martin Orne to examine Bianchi. In the meantime, detectives had discovered that "Steve Walker" was the name of a college student from whom Bianchi had stolen transcripts to set up a fraudulent psychiatric practice, had seen the movie Sybil shortly before his evaluation, and had read numerous psychology books, including a book on the classic MPD case, The Three Faces of Eve. Dr. Orne, an expert on hypnosis, was able to show that Bianchi was faking his hypnotic state and was molding his behavior to fit the diagnosis; for example, after suggesting to Bianchi that most "multiples" have more than two personalities, “Billy” emerged.

Under pressure he admitted to the deception and struck a plea deal. In fact, in a 2015 interview, he described his videotaped multiple personalities as “hypnosis-induced caricatures seemingly mimicking actress Joanne Woodward’s portrayal of “Eve” in the Three Faces of Eve film.”

The Bottom Line

The release of the movie Split has brought new attention to what has become an increasingly rare strategy in an already-rare insanity defense. One reason may be that, since the 1980s, dissociative personality disorder in an insanity plea has rarely been successful as more jurors have assert that, unless an alter was obviously psychotic or delusional, she or he is still responsible for what happened.

From a legal perspective, new research offers both clarity and confusion; a 2016 study offered support for the argument that DID develops after severe trauma (as opposed to a therapist's suggestion) while other research calls into question whether or not one personality can have complete amnesia for what another personality has done. No one wins when a faker gets off or when a truly insane person is convicted; forensic psychologists can best shed some light by researching what the defendant's life was like prior to his arrest and by understanding what genuine DID should look like in a legal context and what it should not.

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