Podcast Summary: The Trial: USA

Episode: Exclusive! Connecting the Unsolved: The Black Dahlia and Zodiac Killer Cases

Hosts: Kayla Brantley (The Crime Desk), Josh Boswell (Senior Reporter, Daily Mail)
Date: December 26, 2025

Overview

This special episode of The Trial: USA explores a startling new theory: that the infamous Black Dahlia murder of 1947 and the Zodiac Killer cases of 1968-1969 might be connected, possibly with the same individual responsible for both. The theory comes from cold case investigator Alex Baber, whose decoding of a Zodiac cipher led him to suspect Marvin Margolis, also known as Marvin Merrill—a known suspect in the Black Dahlia case and now, potentially, the Zodiac himself. Josh Boswell, who has investigated the materials and interviewed those involved, unpacks the evidence and its implications.

Key Discussion Points and Insights

1. Background on Each Case (03:40–05:56)

• The Black Dahlia: In 1947, Elizabeth Short, an aspiring actress, was found murdered and brutally mutilated in Los Angeles. The crime shocked the nation and remains unsolved. Short’s killer taunted the police with letters post-crime.
• The Zodiac Killer: Beginning in 1968 in Northern California, the Zodiac attacked young couples, sending encrypted messages to newspapers and law enforcement. Five are confirmed dead out of at least seven victims. The Zodiac’s identity remains unknown, and he became infamous for his cryptic letters and taunts.

"It was a case that has been unsolved to this day. People are still working on it, have been for decades."
— Josh Boswell (05:20)

2. The Explosive New Theory: Connecting Two Cases (06:09–07:08)

• Investigator Alex Baber claims to have decrypted the Zodiac “My name is...” cipher, which points to Marvin Margolis—also a suspect in the Black Dahlia case.
• Margolis (aka Marvin Merrill) is a central figure due to links with both crimes and is put forward as the main suspect.

"He got a name of someone that might be the Zodiac, and that person, it turns out, is also a suspect in the Black Dahlia killing. And so you've got a potential solution to these two very famous cold cases."
— Josh Boswell (06:41)

3. Who Was Marvin Margolis? (07:08–10:08)

• Margolis was a Marine, served in WWII, and studied medicine at USC, working with cadavers.
• He lived with Elizabeth Short and was in a romantic relationship with her; this ties him to the Black Dahlia murder.
• Margolis was one of 22 suspects in the original FBI investigation, left LA, and returned before the Zodiac killings began.
• Margolis’s military documents indicate aggressive tendencies and a mental health discharge.

"There was this crucial piece of evidence, which was a female police officer who said that a woman who she later realized was Elizabeth Short came up to her hours before the killing was discovered and told her that she was afraid for her life from this crazy ex Marine boyfriend of hers."
— Josh Boswell (08:24)

4. The Cipher Connection and New Evidence (10:56–14:56)

• Alex Baber claims to have solved the Zodiac's Z32 cipher, which allegedly points to Elizabeth Short’s grave—a direct link between Zodiac and the Black Dahlia.
• Unveiled a sketch drawn by Margolis: a nude female torso labeled “Elizabeth," with markings matching Short’s wounds. When enhanced, the word “Zodiac” appears hidden on the sketch.
• Margolis owned a Japanese bayonet similar to the weapon used in the Zodiac’s Lake Berryessa attack; the bayonet has symbols matching Zodiac ciphers and may contain recoverable DNA.

"When you do that, you see in the bottom right hand corner, the word Zodiac emerges, which would just took my breath away at that moment."
— Josh Boswell (13:49)

5. Decoding the Zodiac Cipher (16:29–20:44)

• Baber used methodologies revealed by the 2020 decryption of other Zodiac ciphers, combined with digitized 1950 census data to limit possible names.
• Through repeated character patterns and demographic filters, “Marvin Merrill” uniquely fit the Zodiac’s 13-character cipher.
• Social Security records show Margolis changed his name after the Dahlia murder, connecting his identities.

"The real kind of clever, logical thinking that Alex Baber had here was...the Zodiac was a living male in the United States in 1950, so his name must be in that list...Once you apply those restrictions, you get one name. Marvin Merrill."
— Josh Boswell (18:58)

6. Expert and Law Enforcement Reaction (20:49–22:30)

• Baber’s solution was validated by Ed Giorgio, former NSA codebreaker, who confirmed the approach and findings.
• LAPD, SFPD, and an interagency FBI-led Zodiac task force have been briefed and are seriously investigating the findings.

"You can see that this is being taken seriously, you know, not just by experts, but also by law enforcement."
— Josh Boswell (21:11)

7. Potential Motive and Psychological Connections (22:30–25:20)

• Margolis displayed violent tendencies, an obsession with dissection, and shared idiosyncratic spelling as seen in Zodiac and Dahlia letters.
• Handwriting analysis and other forensic work are ongoing. Misspellings and letter formations seem consistent with Margolis.

8. Margolis' Family and Character (25:20–27:13)

• Margolis’s son is cooperating but skeptical his father was the killer—describes him as intelligent, inventive, but admits to one violent incident that led to divorce.
• The son recalls his father being industrious and bookish but acknowledges a dangerous temper.

"There was this one incident where his sister was in the house...the mother had to get in between them with a knife and threaten her husband, Marvin, to stop him going after their daughter."
— Josh Boswell (26:41)

9. Why the Theory Matters Now (27:13–28:54)

• Closure for victims’ families, especially Zodiac survivor Brian Hartnell.
• Solving these cases, even posthumously, is meaningful: "no matter how long it takes...these cases are going to get solved."

Notable Quotes & Moments

• "He kept on requesting to be moved to the surgical unit, and they denied him and denied him, and then eventually they kicked him out with mental health discharge and...was released from the military."
  — Josh Boswell (09:24)

• "If you take a picture of that sketch...you can expose some scribbles...the word Zodiac emerges, which would just took my breath away at that moment."
  — Josh Boswell (13:34–13:49)

• "This isn't just another person throwing out yet another name. This is a investigation that is being thoroughly looked at by law enforcement."
  — Josh Boswell (21:48)

• "It's also just the concept of justice, right? This is a huge unsolved case...no matter how long it takes, no matter how far away we are in time from these events, these cases are going to get solved."
  — Josh Boswell (28:31–28:49)

Timestamps for Key Segments

• Case Recaps & Historical Context: 03:40–05:56
• The New Theory Outlined: 06:09–07:08
• Profile of Marvin Margolis: 07:08–10:08
• Cipher Decryption Approach: 16:29–20:44
• Law Enforcement Response: 20:49–22:30
• Potential Motive & Evidence Analysis: 22:30–25:20
• Family Reaction & Character Insights: 25:20–27:13
• Broader Significance: 27:13–28:54

Conclusion

This episode stands out for its rigorous, multi-pronged investigation and for treating the controversial new theory with both skepticism and open-mindedness. If substantiated, the claim that Marvin Margolis—already an official suspect in the Black Dahlia murder—could also be the Zodiac would fundamentally shift both the true crime landscape and historical understanding of these notorious cases. The episode underscores the persistent importance of justice and the enduring hope that even the coldest cases may one day be solved.