Did Kenneth Bianchi, The Hillside Strangler, Actually Have Multiple Personality Disorder?

In the late 1970s, Los Angeles residents were fixated on a terrifying question: Who was strangling girls and young women and dumping their bodies around the city? 

 While the arrest of Kenneth Bianchi and Angelo Buono solved the mystery of who was behind 10 brutal murders, it also raised another knotty question. Did Bianchi have multiple personality disorder? 

 Psychiatric experts, it turned out, were sharply divided on the subject at the time of the trial and opinions are still split when it comes to whether the disorder exists at all. 

 Peacock’s four-part docu-series “The Hillside Strangler: Devil in Disguise,” streaming now, provides an illuminating look at how the question of whether Bianchi had multiple personalities played a major role in this infamous case.

 Bianchi was linked to the L.A. stranglings following his arrest in January 1979 for the murder of two women who were attending college in Washington State. 

While in custody, Bianchi began claiming that another personality — Steve Walker — had committed the crimes.

After his arrest, Bianchi’s attorney filed papers with the Whatcom County Superior Court stating that his client had already been examined by three doctors, according to the Peacock special. Those doctors had concluded Bianchi suffered from a severe multiple personality disorder.

As a result, Bianchi was ordered by the court to undergo further extensive psychiatric evaluations.

During these taped sessions, which feature prominently in the Peacock docuseries, Bianchi alternately denied and confessed to the killings in Los Angeles and Washington. Bianchi also claimed that he had multiple personalities, according to the St. Louis Post-Dispatch.

Multiple personality disorder was in the zeitgeist at the time of the murders, thanks to the 1976 TV miniseries “Sybil,” which told the story of a woman who developed multiple personalities because of her traumatic childhood. 

Psychiatric specialists’ responses to Bianchi’s claims varied.

Dr. John Watkins, from the University of Montana, interviewed Bianchi in March 1979. He was a big “proponent of multiple personality,” Dave McEachran, a retired Whatcom County prosecutor, told producers.

In a recorded session in which Bianchi was purportedly under hypnosis, Watkins said: “I have talked a bit to Ken, but I think that perhaps there might be another part of Ken that I haven’t talked to, and I would like to communicate with that other part.”

Bianchi responded: “Call me Steve … I made him kill them …” He then added that the victims were strangled.

Dr. Ralph Allison, a psychiatric expert who’d later publish the book “Minds In Many Pieces,” was chosen by the court to interview Bianchi. 

He is seen using hypnosis and age regression techniques on Bianchi in “The Hillside Strangler: Devil in Disguise.” Allison initially supported the theory that Bianchi had multiple personalities and was therefore incompetent to stand trial.

But people who knew Bianchi, including his former girlfriend Sheryl Kellison, as well as a friend of one of the victims, told producers they never observed any indications of a multiple personality.

Experts recruited by prosecutors came to the same conclusion, including Dr. Martin Orne, an expert on hypnosis with plenty of experience with multiple personality disorder. He gave Bianchi tests to see if he actually had multiple personalities, as seen in the Peacock docuseries, tests which Bianchi failed.

After a series of interviews with Bianchi, Orne “helped convince a judge” that Bianchi’s claim of multiple personalities “was a fabrication,” the New York Times reported in 2000. 

Dr. Saul Faerstein, another psychiatrist selected by the prosecution, also questioned Bianchi. His conclusion, seen in a taped interview obtained by Peacock: “I don’t think he's a multiple personality. He’s a very charming individual who sells himself. I believe he was a salesman for multiple personalities.”

Bianchi eventually admitted in court that he made up his alter-egos, UPI reported. He ultimately pleaded guilty to murders in both Washington and California, which allowed him to avoid the possibility of the death penalty if he was convicted.

To learn more about the case, watch “The Hillside Strangler: Devil in Disguise” streaming now on Peacock.