Billy Milligan: Can Someone With Dissociative Identity Disorder Be Accountable for Violent Crimes?

In October 1977, authorities arrested 22-year-old Billy Milligan and charged him with the kidnapping, robbery and rape of three Ohio State University (OSU) students. An OSU police officer who rode with Milligan to the Columbus, Ohio police headquarters told The Columbus Dispatch in a 2007 interview, "I couldn't tell you what was going on, but it was like I was talking to different people at different times."

During a psychiatric evaluation, Milligan alleged no wrongdoing, blaming one of his alters (or alternate identities), Ragen, for the robberies and another, Adalana, for the kidnappings and sexual assaults. Milligan claimed to have 24 alternate personalities.

On December 4, 1978, in a landmark trial, Milligan became the first defendant found not guilty by reason of insanity due to multiple personality disorder, reclassified in 1993 as dissociative identity disorder.

Joni Johnston, a forensic psychologist and private investigator, has researched and written extensively on the Billy Milligan case. A&E spoke with Johnston to learn more about Milligan's controversial diagnosis, the acquittal and whether the verdict would hold up in a courtroom today.

What was Billy Milligan diagnosed with, who diagnosed him and how has the definition of that diagnosis changed since his trial?

During the trial, Milligan was diagnosed with multiple personality disorder or MPD. He was evaluated by nine different mental health professionals. His most famous evaluator was a woman named Cornelia Wilbur, a psychiatrist best known for the [1973] book 'Sybil,' [which recounted] a groundbreaking [1950s-era] examination of someone who had these multiple personalities with different behaviors and mannerisms. [It followed the 1957 book about the subject,] 'The Three Faces of Eve' [about a woman named Chris Costner Sizemore who was diagnosed with MPD]. These books started a phenomenon. And MPD…was the diagnosis that Milligan received.

[Editor's Note: Sybil, whose real name was Shirley Manson, confessed that she made up her personalities in a letter to Wilbur.]

At the time, it was believed multiple personality disorder was caused by trauma, and that these individuals under trauma, because they couldn't physically escape, mentally escaped by creating these different forms within themselves. It was a controversial diagnosis.

Our understanding as mental health professionals has changed in terms of how we see what MPD was then. Now, it's been renamed dissociative identity disorder, or DID, to reflect a difference in understanding. Rather than having all these different personalities running around, with DID it's more like trauma causes a person to almost not be fully developed. They may kind of split off parts of themselves and have trouble, for example, experiencing certain emotions or feel like they are outside of themselves when they get in certain situations or things don't seem real.

What evidence did Milligan's defense team present to support the claim that he had multiple personalities and was not accountable for his crimes?

Milligan had been in a psychiatric hospital prior to these crimes being committed. He was actually a teenager when he was hospitalized for various psychiatric problems and diagnosed with what was then called hysterical neurosis. There were two subcategories: a conversion type and a dissociative type. The hysterical neurosis dissociative type, which was Milligan's diagnosis, involved alterations in the patient's state of consciousness or identity to produce such symptoms as amnesia, somnambulism [a form of sleepwalking], fugue [a loss of awareness of one's identity] and multiple personality.

Milligan's defense team was able to go back and show that at various points in his upbringing, he had wandered off a few times and was prone to tendencies of spacing out. There was some evidence that he did have some dissociative qualities in his background. Of course, he also claimed a history of trauma, which would be something you would be looking for if you are diagnosing somebody with MPD. He claimed he was sexually abused by his stepfather. [His stepfather denied the claims and was never charged.]

At the time of his crimes, at least one police officer thought he acted very odd and seemed to shift personalities. One of his victims described him as being soft and well-spoken, while another claimed he had an accent. So, there were behavioral observations from other people that suggested he may have had some dissociative symptoms. It becomes a little bit clouded because he also had this extensive criminal history. I do think the social environment and media attention surrounding MPD influenced the way many people conceptualized this case.

Milligan was acquitted by a judge. Did the prosecution challenge the verdict?

They did not challenge the verdict. They accepted the argument because nine different people evaluated him. The judge acquitted him, and the prosecution did not contest the ruling.

Milligan was the first ever defendant found not guilty due to multiple personalities, known now as dissociative personality disorder. Did his case set up any legal precedents?

I'm not an attorney, so I don't want to speak too much to legal precedent. However, I don't think Milligan's case set anything up.

In general, an insanity plea is a tough road to hoe. It was then, and it is even harder now. I can't imagine what legal precedent his case would have set, because they use a diagnosis to argue the existing legal definition of insanity. They were trying to say because of his mental illness he was not able to appreciate that what he was doing was wrong and, therefore, was not criminally responsible. The diagnosis didn't change what was required. Legally, to be found insane, it just said this is an example of what would fit.

Do you think Milligan's defense team would be successful if the case were tried today?

Today, I do not think he would be found legally insane. Most people who commit violent offenses are not mentally ill. When I'm asked to do a criminal responsibility evaluation, this is someone who has potentially committed a violent crime and there is some suspicion or diagnosis of mental illness. The question becomes, 'If this person is mentally ill, did their crime have anything to do with their mental illness?' Most of the time, the answer is no.

In the case of Billy Milligan, for the sake of argument, let's say he did have MPD. In order to be found legally insane, it would be because of his mental illness. What in his mental illness made him commit rape? There needs to be some direct link between a person's symptoms and the crime they committed.

Are there other notable cases where DID was used as a defense? Is it still used in the courtroom—and if so, how often?

There was a case involving a man named Tom Bonney. In November of 1987, he shot his daughter 27 times. Bonney had a preexisting history of mood swings and anger management problems, but there was no evidence of MPD until this particular psychologist named Paul Dell called Bonnie's defense attorney and offered to evaluate him. Until then, no one had thought Bonney had MPD or anything like that. They tried to use this in his defense, but there were all kinds of problems. Foremost, before ever meeting Bonney and evaluating him, the psychologist suggested he had MPD. The opposing psychiatrist, who was for the prosecution, reviewed the evaluation and pointed out all of the times Dr. Dell had been extremely suggestive.

Another famous case involves Kenneth Bianchi, the ‘Hillside Strangler.’ He managed to convince four mental health professionals that his alter, Steve Walker, had committed the murders. He had tried all these other strategies, and nothing was working. Then, all of a sudden, he developed MPD.

Fortunately, there was another psychiatrist who was much savvier and questioned the diagnosis. Bianchi ended up admitting he had lied and received a plea deal to avoid the death penalty.

Can someone with dissociative personality disorder be held accountable for murder or other serious crimes?

There has to be a direct link between the symptoms and the person's criminal behavior. Otherwise, it just becomes, 'This person has committed a violent crime, and they have a mental illness.'

[Editor's Note: In 2014, Milligan died from cancer at the age of 59.]