Killer Minds: Inside the Minds of Serial Killers & Murderers

Episode: MURDEROUS MINDS: The Killer Step-Brother Pt. 2
Release Date: August 21, 2025

Hosts: Vanessa Richardson & Dr. Tristan Engels

Episode Overview

This gripping episode concludes the harrowing two-part exploration into the case of Nathan Matthews, a British Army veteran whose hatred for his teenage stepsister, Becky Watts, escalated into kidnapping, murder, and dismemberment. Hosts Vanessa Richardson and forensic psychologist Dr. Tristan Engels weave together detailed crime storytelling and psychological analysis to examine how complex family dynamics, unresolved resentments, and psychological dysfunctions culminated in a shocking domestic tragedy.

Key Discussion Points and Insights

1. Background and Crime Overview

• Becky Watts' Disappearance (04:53)

  • On February 19, 2015, 16-year-old Becky Watts went missing from her family home in Bristol, UK.
  • Her stepbrother, Nathan Matthews (28), and his girlfriend, Shauna Hoare (21), visited that morning. Matthews arrived masked and equipped with handcuffs, tape, and a stun gun.

• Crime Committed (06:00)

  • Matthews attempted a "fake kidnapping," but the situation escalated when Becky fought back; he used a military chokehold, killing her.

Quote

“He stormed in to find his stepsister, then taped her mouth shut...The specific sequence of events isn't clear, but during the ensuing scuffle, Nathan punched Becky...then grabbed her throat and utilized a technique he'd learned in military school to restrict blood flow to the head. When he did this, she stopped fighting back, and she also stopped breathing. Becky was dead.”
— Vanessa Richardson (06:41)

2. Psychological Analysis of the Perpetrator

• From Fantasy to Reality (07:17)
  • Dr. Engels explains how sexualized, violent fantasies can embolden individuals to attempt real crimes but rarely unfold as imagined.
  • Resistance from real victims can trigger escalation from fantasy to violence.

Quote

“For individuals like Nathan, the fantasy offers something intoxicating. It's power without consequence. But reality never plays out the way it does in the fantasy...”
— Dr. Tristan Engels (07:25)

• Traits of Siblicide Perpetrators (08:11)
  • Chronic resentment, jealousy, history of neglect, family dysfunction, and emotional dysregulation are common threads.
  • Siblicide is rare, accounting for only 1-3% of homicides.

3. Cover-Up and Aftermath

• Matthews’ Behavior Post-crime (09:16)
  • He hid Becky’s body in his car and carried on as if nothing happened, watching TV with family and later acting as a concerned stepbrother.
  • Social media was used to feign concern and control the narrative.

Quote

“Nathan helping his stepfather post on Facebook about Becky's disappearance is a perfect example...it allows them to manage how others see them...he would feel a perverse sense of power in knowing he holds the truth.”
— Dr. Tristan Engels (11:51)

• Organized Dismemberment and Evidence Concealment (12:51 – 15:20)
  • Matthews purchased tools and cleaning supplies, dismembered Becky, and enlisted Shauna’s help in bagging remains.
  • Their absence from search efforts raised suspicions among friends and family.

Quote

“Their behavior isn't atypical...They lean into rationalization, compartmentalization, and arrogance, trying to maintain some resemblance of control.”
— Dr. Tristan Engels (15:20)

4. Criminal Investigation

• Turning Points

  • Forensic teams found a bloody fingerprint belonging to Nathan on Becky’s doorframe (19:00).
  • Both Nathan and Shauna’s stories were suspiciously coordinated during police interviews.

• Interrogation Techniques and Confession (20:12 – 24:15)

  • Nathan’s calm attitude contrasted with his earlier avoidance, suggesting impression management.
  • He revealed his resentment towards Becky, providing motive.

Quote

“His calm, joking demeanor could reflect several things...emotional detachment, ability to compartmentalize stress, or a strategic attempt to appear cooperative.”
— Dr. Tristan Engels (20:12)

Quote

“People sometimes reveal underlying emotions or beliefs without realizing how significant that disclosure is. In Nathan's case, he may have become desensitized to the weight of what he was saying.”
— Dr. Tristan Engels (22:58)

5. Resolution and Legal Proceedings

• Evidence and Arrests (24:15 – 27:17)

  • Forensic evidence proved Nathan’s involvement. Both Nathan and Shauna were arrested on February 28, 2015.

• Confession and Motive (27:17 – 27:55)

  • Under overwhelming evidence, Nathan confessed via his lawyer, arguing he hadn’t planned to kill Becky, and denied Shauna’s involvement.

Quote

“A confession may reflect a strategic response to overwhelming evidence...in order to regain a sense of control, minimize the consequences, or protect someone else.”
— Dr. Tristan Engels (27:17)

• Trial and Psychological Theories (34:23)
  • During trial, Shauna was portrayed as a victim of Nathan’s control, with one criminologist suggesting a “folie à deux” (shared psychosis).
  • Dr. Engels clarified this likely wasn’t classic shared psychosis, but rather coercive control and trauma bonding.

Quote

“What this reflects more accurately...is behavior often driven by the need to appease their dominant partner...This stems from fear, psychological dependency, coercion, isolation, trauma bonding...”
— Dr. Tristan Engels (34:23)

• Verdicts and Sentencing (37:34)
  • Nathan was convicted of murder (life sentence, minimum 33 years); Shauna of manslaughter (17 years).

Notable Quotes & Memorable Moments

• On Post-Offense Behavior:

  “Nathan has been living in that duality for most of his life.”
  — Dr. Tristan Engels (15:20)

• On Compartmentalization:

  “That once again, speaks to his capacity to compartmentalize not just emotions, but even morality, but also his continued need for control.”
  — Dr. Tristan Engels (31:41)

• On the Outcome:

  “Both Becky and Nathan were raised in similar circumstances...but Becky rose above it. Nathan let his troubles consume him and as a result, he destroyed both of their lives.”
  — Vanessa Richardson (37:34)

Important Timestamps

| Timestamp | Segment Description | |-----------|-------------------------------------------------------------| | 04:53 | Details of the crime and Becky's death | | 07:17 | Analysis of fantasy-driven violence | | 08:11 | Psychology of siblicide | | 09:16 | Cover-up and post-crime family interactions | | 11:51 | Analysis of Nathan’s social media behavior | | 12:51 | Purchasing and use of dismemberment tools | | 15:20 | Psychology of offenders covering up crimes | | 19:00 | Discovery of forensic evidence (bloody fingerprint) | | 20:12 | Nathan's interview demeanor | | 22:58 | Subconscious slips and establishment of motive | | 24:15 | Shift from missing persons to murder investigation | | 27:17 | Confession and reasons behind it | | 34:23 | Folie à deux and co-offender psychological dynamics | | 37:34 | Trial verdicts, sentencing, and family aftermath |

Closing Reflections

The episode ends with a reminder of the devastating consequences of unchecked hatred and dysfunctional family dynamics. Despite similar life circumstances, Becky overcame her challenges while Nathan allowed his to manifest violently, destroying two lives and leaving deep scars on their family.

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