Podcast Summary: 48 Hours – Post Mortem | The Boy Who Killed His Twin
Date: September 30, 2025
Host: Ann Marie Green
Guest: Erin Moriarty
Main Theme:
This “Post Mortem” episode takes listeners behind the scenes of the gripping “48 Hours” season premiere investigating the perplexing case of Ben Elliot, a 17-year-old who stabbed and killed his autistic twin sister, Megan, in 2021—a case that left even seasoned correspondents divided over guilt, motive, and mental state. Erin Moriarty and Ann Marie Green explore the tangled interplay of forensic psychology, absence of motive, family trauma, and how the court system grapples with the rare “sleepwalking defense.”
Main Discussion Points & Key Insights
The Unique Challenge of the “Sleepwalking Defense”
- Case Overview (01:34)
- Ben Elliot admits to stabbing his twin sister but claims he was sleepwalking and did not intend harm.
- The episode keeps both correspondents—and likely listeners—constantly reevaluating Ben’s guilt or innocence.
- Erin’s Perspective as a Twin (03:36)
- Erin, herself a twin, shares the personal difficulty in reporting on such a case, noting the unusual lack of motive or sibling conflict.
- Quote (Erin Moriarty, 03:36): “I can't in a million years imagine hurting my twin. It's the person I knew before anybody.”
Dissecting the Investigation and Lack of Motive
- No Clear Motive (04:04–05:49)
- Prosecution asserts intentional murder but cannot provide a motive.
- Evidence shows Ben was protective toward Megan; no texts, social media, or other records suggesting animosity.
- Quote (Erin Moriarty, 04:23): “Everyone that the prosecution talked to said that Ben loved his sister and loved being her protector.”
- Technological Evidence Gaps
- No search history indicating a staged sleepwalking defense; both twins’ prolific phone use yielded no relevant digital evidence.
The Science and Mystery of Sleepwalking
- Public (and Juror) Perceptions (05:49–08:13)
- Misconceptions abound; sleepwalking can indeed involve complex behaviors like cooking.
- “Parasomnia” (including sleepwalking and sleep-eating) is real and not as rare as most believe, but violent acts in this state remain extremely rare.
- Quote (Erin Moriarty, 06:26): “It's more common than I realize it is, but crimes committed while you’re sleepwalking is less common, although it does happen.”
- Critical challenge: No witnesses in most sleepwalking cases; reliance on expert testimony becomes central.
- Expert Disagreement
- Defense and prosecution experts agreed sleepwalking (parasomnia) exists but disagreed about memory retention and consciousness during events.
- Dr. Pressman (prosecution) argues Ben’s memory of the stabbing indicates wakefulness.
- Quote (Anne Marie Green, 09:00): “How did he know how quickly he came out of it? Because there were only two people in that room.”
The Role of Demeanor and 911 Call
- Ben’s Affect and the 911 Call (10:03–11:13)
- Ben’s soft, “whispery” voice in the 911 call is interpreted by prosecutors as suspicious.
- Erin notes Ben’s low affect is consistent with his personality.
- Quote (Erin Moriarty, 10:34): “He is very soft spoken, and he doesn’t show a lot of emotion. And what he said to me was that he wasn’t whispering, that that’s how he talks.”
- Why Not Call for Parental Help?
- Debate ensues over Ben’s failure to alert his parents, possibly explained by the unique closeness of twins, as posited by Erin.
Public Understanding of Sleepwalking and Impact on Jury
- Juror Familiarity (12:14–14:31)
- Many involved (prosecutors, jurors, witnesses) have direct or indirect experience with sleepwalking, aiding in understanding the defense, but none had encountered sleepwalking-related crimes.
- Dr. Pressman testifies that actions like unsheathing a knife are too complex for a sleepwalking individual—a point challenged by known cases of complex sleep acts, even crime.
The Crime Scene: Body Cam Footage and Parental Reaction
- Body Cam Insights (15:54–17:02)
- Police withholding information from distraught parents is seen as protective of the investigation.
- Family's Legal Consult and Prosecution Tactics
- Parents call a lawyer friend for guidance; prosecutors frame this as evidence of a cover-up, a move the family claims was out of confusion and fear.
- Quote (Erin Moriarty, 18:12): “They were very upset with the idea that anyone would accuse them of a cover up.”
Ben’s Interrogation and Behavioral Interpretation
- Police Footage and Erin’s Interview (19:12–21:16)
- Ben’s subdued, factual demeanor noted both in police interviews and Erin's jailhouse visit.
- Odd comments—like talking about taking the SAT after the stabbing—are explained by Ben as emotional shutdown.
Evidence and The Verdict
- Key Factors for Jurors (21:58–23:21)
- Major considerations: multiple stab wounds, depth of wounds, and Ben’s behavior (including use of a pillow, which prosecution interprets as smothering Megan).
- No definitive motive; prosecution urges that “you never know what goes on behind closed doors.”
- The Verdict & Sentencing (23:21–25:24)
- Initial jury split (seven for guilty, five for not guilty), but ultimately unanimous for first-degree murder.
- Sentenced to 15 years (eligible for parole in 2032).
- Noteworthy: at least one juror requested leniency, indicating interior conflict within the jury.
- Quote (Erin Moriarty, 24:44): “[Ben] points out that the judge could have sentenced him to 40 years, but instead chose to sentence him to a much shorter period of time. And he said to me… if people really thought that he had killed his sister in cold blood, wouldn’t they want him locked up for the rest of his life?”
Aftermath: Family Grief and Ongoing Questions
- Family’s Pain and Coping (25:44–26:53)
- Parents (Michael and Kathy), devastated and bewildered, struggle with the double trauma of Megan’s death and Ben’s incarceration.
- Family’s unity stands out as they support each other through overwhelming grief.
- Quote (Erin Moriarty, 26:53): “They just held hands through the whole thing. And… said, ‘we couldn’t have gotten through it without each other.’ And that was very touching to me.”
- Ben remains hopeful as he appeals the verdict.
Notable Quotes & Timestamps
- On twin bonds and the case’s emotional impact:
- “I can't in a million years imagine hurting my twin. It's the person I knew before anybody.” – Erin Moriarty (03:36)
- On lack of motive and digital evidence:
- “Everyone that the prosecution talked to said that Ben loved his sister and loved being her protector.” – Erin Moriarty (04:23)
- On the rare intersection of sleepwalking and violence:
- “It's more common than I realize it is, but crimes committed while you’re sleepwalking is less common, although it does happen.” – Erin Moriarty (06:26)
- On Ben’s emotional presentation:
- “He is very soft spoken, and he doesn’t show a lot of emotion. And what he said to me was that he wasn’t whispering, that that’s how he talks.” – Erin Moriarty (10:34)
- On the painful aftermath for the family:
- “They just held hands through the whole thing… they said we couldn’t have gotten through it without each other. And that was very touching to me.” – Erin Moriarty (26:53)
- On the ambiguity of intent and guilt:
- “[Ben] points out that the judge could have sentenced him to 40 years, but instead chose to sentence him to a much shorter period of time. And he said to me… if people really thought that he had killed his sister in cold blood, wouldn’t they want him locked up for the rest of his life?” – Erin Moriarty (24:44)
Timeline of Key Segments
- 01:34 – Case introduction, Ben admits stabbing, claims sleepwalking, no established motive
- 03:36 – Erin discusses her perspective as a twin
- 05:49–06:26 – Misconceptions, prevalence, and complexity of sleepwalking
- 09:00 – Expert disagreement over memory/awareness in sleepwalking
- 10:03–11:13 – Analysis of Ben’s 911 call and demeanor
- 12:14–14:31 – Juror/prosecution perspectives on sleepwalking, consciousness, and intent
- 15:54–17:02 – Body cam footage and family’s immediate response
- 19:12–21:16 – Ben’s police interrogation and Erin’s insights from her interview
- 22:10–23:21 – Key jury evidence and deliberations
- 23:21–25:24 – Verdict, sentencing, and juror leniency request
- 25:44–26:53 – Family grief and coping after the verdict
Tone and Takeaway
Reflecting the signature tone of “48 Hours,” the episode is thorough, empathetic, and unflinching. Both correspondents grapple with their own impressions, openness to doubt, and the limits of what proof and motive can be expected in a court of law—especially in cases where the mind’s shadowy workings complicate clear-cut conclusions. Listeners come away with an appreciation for the legal, psychological, and human complexities at the heart of this tragic case and are left to wrestle with the same uncertainties and emotional resonance that stay with the journalists who reported it.