Everything You Need To Know About Billy Milligan’s Case From Monsters Inside

Milligan was arrested for three rapes in 1977 but claimed the crimes were committed by one of his alternate personalities.

by Justice Namaste
A photo of Billy Milligan, an accused rapist who is the subject of Netflix's new docuseries 'Monster...

Content warning: This post includes discussion of sexual assault.

Netflix’s new four-part docuseries, Monsters Inside: The 24 Faces of Billy Milligan, revisits the infamous case of Billy Milligan, who became the first person to be acquitted of a violent crime using the defense of criminal insanity. After three rapes occurred at Ohio State University in the late ‘70s, one of the victims identified her assailant as Milligan, a young man living in the area who already had a criminal record for rape and robbery. Upon his arrest in 1977, however, Milligan appeared to have no memory of committing the crimes.

Because a gun had been used in the crimes and guns were found at his residence, Milligan, then 22, was indicted on three counts of kidnapping, three counts of aggravated robbery and four counts of rape. He was held at the Ohio State Penitentiary, where he underwent psychological evaluation and was eventually diagnosed with dissociative identity disorder, then known as multiple personality disorder. Milligan’s lawyers argued that Milligan’s personality had begun to splinter during childhood, when he experienced alleged abuse at the hands of his stepfather Chalmer Milligan (Chalmer always denied the allegations against him). Their legal defense hinged on the idea that Milligan couldn’t be held responsible for the assaults because they weren’t committed by his main personality. His lawyers also argued that his condition prevented him from knowing right from wrong and cooperating with his legal counsel.

The legitimacy of Milligan’s diagnosis was debated by both medical professionals and the general public, leading to widespread media coverage of the case and feeding into an enduring curiosity with DID. Ultimately, Milligan was found not guilty due to criminal insanity, and he was committed to a state-run mental hospital. In total, psychiatrists determined that at least 24 different personalities seemed to exist within Milligan’s mind. These reportedly included a British intellectual named Arthur who studied science and medicine, an Eastern European named Regan who was referred to as the “keeper of hate,” and a teenage lesbian named Adalana who Milligan said was the personality behind the rapes. Milligan also claimed to be able to speak and write in a number of languages as a result of his alters.

Several years after being institutionalized, Milligan escaped from Central Ohio Psychiatric Hospital on July 4, 1986. He allegedly obtained fake documents under the name Christopher Carr and settled in Bellingham, Washington, where he began living with Michael Madden. When Madden went missing two months later, Milligan fled the state but was soon captured by police in Florida. No one has ever been convicted in Madden’s disappearance, but Milligan had been cashing Madden’s disability checks in a shared bank account.

After that, Milligan was sent back to a mental hospital in Ohio. He was released in 1988 after an independent psychiatrist concluded that he was no longer a danger to society. In August 1991, he was released from all state supervision. Not much is known about Milligan’s life during this period, though there is record of him living in California, and his sister says he subsequently moved back to Ohio and lived in a mobile home she purchased for him. In 2014, Milligan died from cancer at the age of 59. His life story was popularized in Daniel Keyes’ 1981 non-fiction novel, The Minds of Billy Milligan, which served in part as inspiration for M. Night Shyamlan’s 2016 movie Split.

If you or someone you know has been sexually assaulted, you can call the National Sexual Assault Telephone Hotline at 800-656-HOPE (4673) or visit