By
Murray Weiss
September 26, 2025 / 7:30 AM EDT
/ CBS News
In the early morning hours of Sept. 29, 2021, Benjamin Elliott, then 17 years old, walked into his twin sister Meghan’s bedroom. It was something he had done hundreds of times. But on this morning, he had a knife in his hand and stabbed her in the neck while she was asleep. He would later say he was sleepwalking. When he realized what he had done, he immediately called 911.
“I just killed my sister,” Benjamin told the emergency operator. “Oh my God … I thought it was a dream.”
Benjamin’s parents Kathy and Michael Elliott faced a heartbreaking and unimaginable reality: their beloved daughter, Meghan, was dead, and her adoring twin brother — their son — was accused of intentionally murdering her. They could not imagine why, and neither could investigators. Correspondent Erin Moriarty investigates the extraordinary case of “The Boy Who Killed His Twin,” for the 38th season premiere of “48 Hours,” airing Saturday, Sept. 27 at 10/9c on CBS and streaming on Paramount+.
“What makes you so sure that you stabbed your sister while you were sleepwalking?” Moriarty asked Benjamin Elliott in a jailhouse interview earlier this year.
“I would never have done that,” he replied. “I loved her. … She was my best and closest friend.”
Benjamin’s family, relatives and closest friends agreed. “He and Meghan are so close, you could never picture anything bad happening between them,” Drue Whittecar, a longtime family friend of the Elliotts, told Moriarty.
“And how did she feel about Ben?” Moriarty asked.
“She loved him,” Whittecar replied. “She looked up to him. … You would see her walk up next to him when she would feel uncomfortable and just kinda stand by him.”
Moriarty also interviewed the prosecutors, Megan Long and Maroun Koutani.
“Were you able to find any evidence that there was a problem with … these twins?” Moriarty asked. “No,” Long replied. “We definitely looked into it and tried.”
So how could such a seemingly loving relationship between the twins end in an unfathomable tragedy?
That’s what Benjamin’s parents — Kathy, a senior manager with the Girl Scouts of America, and Michael, a stay-at-home dad — and their eldest daughter, Elizabeth, wanted to know.
The Elliotts initially feared that a mental health crisis was the cause. But it turned out that Benjamin, and some close relatives of the Elliotts, had a history of sleepwalking. In fact, a boyhood friend of the Elliott twins told their parents about a slumber party years earlier, when they found Benjamin eating a donut on a couch — while he was asleep.
Benjamin’s defense attorneys, Cary Hart and Wes Rucker, asked Dr. Jerald Simmons, a neurologist and sleep disorder expert, to examine Benjamin. Simmons was initially skeptical. But after interviewing Benjamin, and hearing about his and his family’s history of sleepwalking, Simmons conducted two sleep studies on him, with the teenager hooked up to devices that monitored his every movement. Simmons went from skeptic to believer.
He determined that Benjamin fell quickly into what is known as slow-wave sleep, or when people can sleepwalk. That’s important because on the night Meghan was killed, Benjamin spent hours scrolling the web on his cell phone, except for a 24-minute period when his phone was inactive. Simmons believes that Benjamin was sleepwalking during that period, and unintentionally stabbed Meghan to death.
“Do you believe Ben killed his sister without even realizing he was doing it in his sleep?” Moriarty asked Simmons.
“Yes,” he replied. “Ben definitely killed his sister. He did it, there’s no question, he’s the one that had the knife and he stabbed her. But … he didn’t do this voluntarily. There was no motivation.”
Surprisingly, sleepwalking has proved to be a successful — albeit rare — criminal defense. For example, a Canadian man, Kenneth Parks, was accused of driving 14 miles to his mother-in-law’s home, where he killed her. He claimed he was sleepwalking the entire time and was acquitted. And North Carolina father Joseph Mitchell, accused of strangling one of his children, said he was sleepwalking during the killing. He was also found not guilty.
The Elliotts were relieved, and frightened, at finally having an explanation. “It’s scary as hell,” Kathy Elliott said, adding, “if that can happen to us, then that could happen to anybody with a sleep problem.”
They hoped Simmons’ findings would end the investigation into Benjamin. After all, prosecutors admitted they could find no reason for the fatal stabbing.
But prosecutors were still not convinced. They questioned Benjamin’s account of that night, his demeanor during an interrogation with a homicide detective and that he said he stabbed his sister once. That was important because the medical examiner determined Meghan had two wounds to her neck — and one was four inches deep and severed key arteries, which prosecutors believed should have left blood spatter at the scene.
Despite receiving Simmons’ findings, prosecutors charged Benjamin with intentionally murdering his twin, and earlier this year, Benjamin stood trial.
The Elliotts had lost their daughter. No one knew why. Now, they faced losing their son.
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