20/20 After Show: What the Killer Left Behind

Date: February 2, 2026
Host: Deborah Roberts (B)
Guest: Dr. Casey Jordan, Criminologist, Attorney, and Podcast Host (C)

Overview of the Episode

This episode of 20/20’s After Show dives deep into the investigation and resolution of the murder case of Amanda Plass, a 20-year-old aspiring artist and waitress found stabbed to death in her Massachusetts apartment. Host Deborah Roberts is joined by criminologist Dr. Casey Jordan to analyze the case, the investigative process, and the clues that led to an arrest after years of uncertainty. The conversation also explores the forensic details of the case, the psychological motives behind the crime, and evolving legal concepts around youthful offenders.

Key Discussion Points and Insights

1. The Role and Insight of a Criminologist

[02:33]

• What is a criminologist?

  • Dr. Jordan clarifies that criminology is about understanding the why behind a crime, using an interdisciplinary approach combining sociology, psychology, politics, and economics.
    • Quote:
      “We are looking for the why behind the crime... when we understand why, perhaps we can prevent it. It is always with an eye towards prevention.”
      — Dr. Casey Jordan [03:03]

• Criminalistics vs. Criminology:

  • Criminologists focus on broader theories and motivations, not just the physical evidence.

2. Early Stages: Crime Scene and Suspects

[03:48]-[08:14]

• Crime Details:

  • Amanda Plass found brutally stabbed in her kitchen; multiple wounds, including to her sides and through her heart.
  • Stabbing suggests a personal, emotionally-driven crime.
    • Quote:
      "Stabbing is a very personal way... you have to be really determined to stab somebody."
      — Dr. Casey Jordan [05:10]

• Police Focus on Those Closest:

  • Statistically, most female victims know their attacker.
    • Quote:
      "About 80 to 85% of women who are murdered, the culprit is going to be somebody they know or knew intimately."
      — Dr. Casey Jordan [05:43]

• Initial Suspect:

  • Her boyfriend, Seth Green, was the first suspect due to statistical likelihood and his emotional reaction.
  • Seth was cleared with an alibi; he was at work at the time.
    • Quote:
      "When I first heard ... statistically, Seth Green is your guy in most cases like this, the new boyfriend..."
      — Dr. Casey Jordan [06:36]

3. The Case Grows Cold and Family Persistence

[08:58]-[13:34]

• Case Stalls:

  • With no new leads after clearing Seth, police interview 200+ people with no results. Case becomes cold.
    • Quote:
      "If you don't get anything new in the first year, the case will grow cold."
      — Dr. Casey Jordan [09:14]

• Family's Relentless Pursuit:

  • Amanda’s mother, Michelle, keeps pressure on police, hosts public events, hands out flyers, and is “like a junior profiler,” ensuring the case does not fade away.
    • Quote:
      “Michelle... would not let the police let it go cold. She constantly contacted them...”
      — Dr. Casey Jordan [12:50]

4. The Breakthrough: A Clue in Plain Sight

[13:34]-[16:03]

• The Whiteboard Clue:

  • Police revisiting evidence notice a whiteboard in Amanda’s room bearing the phrase “Dennis was here” dated August 11, 2011.
  • This clue had initially been dismissed as an artist’s doodle, but Michelle had kept the board.

• Connecting the Name:

  • Police cross-reference the name Dennis and phone records, leading to Dennis Rosa Roman, a local 19-20-year-old known drug dealer.
    • Quote:
      "In a totally different room... was a whiteboard... it was full of doodles and sketches, because Amanda was an artist. And written on the side... was Dennis was here... with a date."
      — Dr. Casey Jordan [13:42]

5. Investigation Focuses on Dennis Rosa Roman

[16:03]-[17:33]

• Dennis’ Interrogation:

  • His story is inconsistent; he variously denies knowing Amanda, then admits to being there, attempting to justify the presence of his DNA.
    • Quote:
      “When you tell the truth, you don't have to remember what you said.”
      — Dr. Casey Jordan [16:37]

• Forensics:

  • His DNA is matched to evidence under Amanda’s fingernails.
  • Bloody footprints match a rare size 7.5 men’s shoe that he wore.
    • Quote:
      “They know they've got their guy.”
      — Dr. Casey Jordan [16:51]

6. Motive, Conviction, and the Court Case

[18:57]-[21:17]

• Motive Discussion:

  • Stabbing is seen as overkill, suggesting rejection or a crime of passion.
    • Quote:
      "When you see somebody stabbed so many times... you see anger... overkill. That suggests rejection."
      — Dr. Casey Jordan [19:13]

• Conviction:

  • Dennis Rosa Roman is convicted of first-degree murder; DNA and crime scene photos are crucial to the prosecution.
    • Quote:
      “When you put this evidence in front of a jury, this is something that the intent is right there in the photographs.”
      — Dr. Casey Jordan [20:45]

7. Sentencing, Parole Eligibility, and Controversy

[21:17]-[23:36]

• Law Change:

  • Massachusetts law now bars life without parole for offenders under 21, based on new brain science.
  • Dennis, convicted at age 20, is eligible for parole in 2028 after 15 years served.
    • Quote:
      "Under the Massachusetts law, it is considered cruel and unusual punishment for someone to be sentenced to life without the possibility of parole... Dennis was just a few months shy of being 21."
      — Dr. Casey Jordan [21:48]

• Dr. Jordan’s Perspective:

  • She is skeptical of the new law, arguing 20-year-olds know right from wrong and should be sentenced as adults.
    • Quote:
      “20 year olds are not children. They know right from wrong. And if it had just been a few months in the future, he would have been. Life in prison would have stuck.”
      — Dr. Casey Jordan [23:09]

• Family’s Reaction:

  • Amanda's family will likely contest parole at every hearing.

8. Reflections and Case Conclusion

[23:43]-[24:07]

• Dr. Jordan plugs her podcast, Criminal Appeal, focusing on in-depth analysis of cases she’s covered—offering a unique academic and legal perspective.

Notable Quotes & Memorable Moments

• On the emotional intensity of stabbing:
  "You can actually smell the copper in the air from the blood flow. It is emotionally, you have to be really determined to stab somebody."
  — Dr. Casey Jordan [05:10]

• On the power of persistence:
  “If you want that case to be solved, it is so often the family members who are calling those detectives... She would not let the police let it go cold.”
  — Dr. Casey Jordan [12:34]

• On lying in interrogations:
  “When you tell the truth, you don't have to remember what you said.”
  — Dr. Casey Jordan [16:37]

• On age and culpability:
  “I would argue that a 20-year-old knows right from wrong. I actually think that from age everyone should be treated as an adult. I'm not a fan of this new law, to be honest.”
  — Dr. Casey Jordan [23:00]

Timestamps for Key Segments

• Introduction of case and guest: [00:49]–[03:48]
• Crime scene analysis & early investigation: [03:48]–[08:14]
• Case goes cold & family’s involvement: [08:58]–[13:34]
• Whiteboard clue leads to suspect: [13:34]–[16:03]
• Interrogation and evidence on Dennis Rosa Roman: [16:03]–[17:33]
• Discussion of motive and overkill: [18:57]–[19:40]
• Trial, conviction, and jury impact: [19:40]–[21:17]
• Sentencing, law change, and parole debate: [21:17]–[23:36]
• Closing, podcast plug, and final thoughts: [23:43]–[24:07]

Final Takeaway

The episode illuminates the persistent, detail-oriented nature of crime solving, the importance of small overlooked clues, and the sometimes controversial impact of evolving legal standards. Dr. Casey Jordan’s expert commentary offers listeners a nuanced understanding of the investigation, the motivations behind violent crime, and the complex interplay of justice and psychology in the criminal justice system.