Killer Minds: Inside the Minds of Serial Killers & Murderers

Episode: MURDEROUS MINDS: The Killer Step-Brother Pt. 1

Release Date: August 18, 2025
Hosts: Vanessa Richardson & Dr. Tristin Engels, forensic psychologist

Episode Overview

This episode delves into the psychological profile, family dynamics, and escalating violence of Nathan Matthews—a British Territorial Army veteran whose obsession and animosity toward his stepsister, Becky Watts, ended in tragedy. Hosts Vanessa Richardson and Dr. Tristin Engels unpack the early traumas, isolation, addiction to violent pornography, and intertwined relationship factors that led to Nathan’s transformation from isolated child to a killer.

Key Discussion Points & Insights

Early Life and Family Dynamics

• Nathan’s Isolated Childhood (04:39–09:11)
  • Raised primarily by his mother Angie and later by his grandparents due to Angie’s abusive relationship.
  • Diagnosed with fibromyalgia, causing chronic pain, anxiety, and depression.
  • Early feelings of abandonment, inadequacy, and lack of identity.

“...even after that relationship ended, he remained separated from her. That alone can cause confusions, feelings of inadequacy, low self worth, even abandonment.”
— Dr. Tristan Engels (06:08)

• Commentary on Chronic Pain & Psychology (06:08–09:11)
  • Chronic illness isn’t a direct cause of violence, but it can heighten frustration and emotional dysregulation, especially without support.
  • The frustration-aggression hypothesis discussed—frustration from blocked goals can breed aggression.

“Chronic illness often strips away a person’s sense of agency ... identifying areas where they can exercise control...can help restore a sense of purpose and stability.”
— Dr. Engels (07:12)

Nathan’s Adolescence and Dysfunctional Blended Family

• Blending Families & Step-Sibling Rivalry (09:11–14:06)
  • Angie’s new partner Darren has two children, including Becky.
  • Nathan feels displaced, resents Becky for receiving the maternal attention he lacked.
  • Army cadets and mentorship from Darren provided short-lived stability, but did not resolve underlying emotions.

“Nathan...perceived the others as more bonded or aligned…this can further blur his sense of role and belonging, leaving him confused about his place in the family and intensifying feelings of exclusion or resentment.”
— Dr. Engels (12:27)

Escalation: Pornography Addiction & Aggressive Behavior

• Self-Isolation & Pornography Addiction (09:11–11:36)

  • Nathan’s social withdrawal and exposure to pornography started in adolescence, evolving into addiction.
  • The addiction began distorting his reality and how he viewed relationships and sexuality.

• Aggressive Military Behavior & Early Warning Signs (14:06–16:55)

  • Involvement in the army brought out more aggression and bullying.
  • Disturbing comments about morgue access and erratic, dangerous behavior noted by peers.

“He would snap in an instant, like his latent emotional issues were just brewing beneath the surface, waiting to escape.”
— Vanessa Richardson (15:28)

Fixation on Teenage Girls & Becky

• Sexualized Focus on Underage Girls (16:55–19:50)
  • At 18, Nathan becomes sexually interested in his 8-year-old stepsister, Becky—touching her inappropriately and threatening to kill her.
  • Develops a pattern of pursuing and eventually dating much younger girls, most notably 14-year-old Shauna Hoare when he was 21.

“It’s a fundamental distortion in how they view power, intimacy, and consent...They tend to feel chronically inadequate in adult relationships. And so they seek out children or teenagers because they’re more easily imprisoned, oppressed, less confrontational, and less likely to reject them.”
— Dr. Engels (16:55)

The Nathan & Shauna Relationship: Toxic Pair and Enablers

• Dynamic with Shauna Hoare (21:26–29:06)
  • Relationship started when Shauna was underage and quickly turned controlling, with Nathan dictating all aspects of her life.
  • Nathan’s pornography addiction shaped his expectations, leading to coercive, abusive, and manipulative behaviors.
  • Intimate partner violence was routine, including physical and psychological abuse, control over finances, and forced isolation.

“He systematically created an environment in which Shawna's autonomy, her relationships, even basic bodily needs were tightly regulated by him. This is not a mutual partnership. This is a form of captivity.”
— Dr. Engels (26:16)

“Shauna’s identifying with the aggressor...the hope is they will see them as an ally, not a threat. It’s not about true agreement. It’s about actively reducing the risk.”
— Dr. Engels (27:50)

Escalation of Violence and Shared Fantasies

• Fantasies About Kidnapping (29:17–32:10)

  • The couple bonded over violent sexual fantasies, specifically about kidnapping and abusing schoolgirls—often in explicit text messages.
  • Relationship remained outwardly “functional,” even as their private world grew more depraved.
  • Shauna became complicit, emboldening Nathan’s obsessions and hatred toward Becky.

• Family Tragedy and Becky as a Target (32:10–38:06)

  • Nathan's fixation evolves into full-blown rage for Becky, interpreting every minor slight as disrespect.
  • Both Nathan and Shauna become obsessed with the idea of punishing Becky.

“Becky became a symbol of what he lacked...Because she was more vulnerable and accessible, she became the one he punished, not for what she’d done...but for what she represented.”
— Dr. Engels (36:50)

The Crime Plan and Abduction

• Planning the Kidnapping (38:06–41:09)
  • Nathan meticulously prepares a “kidnap kit” to abduct Becky while the family is out, demonstrating fantasy rehearsal and premeditation.

“Fantasy rehearsal is a key warning sign in forensic psychology. People like Nathan...mentally script the scenario until it becomes not just familiar, but rewarding. Eventually the fantasy isn’t enough. And that’s when they begin to plan.”
— Dr. Engels (40:03)

• Execution of the Plan (41:52)
  • On February 19, 2015, Nathan uses the spare key to enter the house with Shauna, abducts Becky, and restrains her.
  • Shauna’s role in the crime is implied, if not direct.
  • Becky’s disappearance initiates an immediate, but ultimately futile, search.

Notable Quotes and Moments

• On control and violence:
  “Nathan’s behavior reflects a pattern of coercive control…This is a form of captivity.”
  — Dr. Engels (26:16)

• On identification with the aggressor:
  “Shauna’s identifying with the aggressor…and in her mind, if she aligns herself with her abuser…the hope is that they will see them as an ally, not a threat. It’s not about true agreement. It’s about actively reducing the risk.”
  — Dr. Engels (27:50)

• On fantasy turning into crime:
  “Fantasy doesn't have limits. There's no empathy, no consequences...The longer someone stays in that psychological loop, the more desensitized they become...Eventually, the fantasy isn't enough. And that's when they begin to plan.”
  — Dr. Engels (40:03)

• On displacement of rage:
  “Becky was never the true source of Nathan’s rage. She just became the unfortunate target of it…This wasn’t about Becky. It was about Nathan’s need to express his pain and his inability to do it directly with the person who caused it.”
  — Dr. Engels (36:50)

Important Timestamps

• 00:54 – Introduction of Nathan Matthews and his family background
• 06:08 – Dr. Engels explains the psychological toll of chronic illness and early separation
• 09:11 – How isolation and pornography addiction took hold
• 14:06 – Shift to military life and emerging dark behaviors
• 16:55 – Escalation of inappropriate and violent tendencies
• 21:26 – The beginnings of Nathan and Shauna's toxic relationship
• 26:16 – Analysis of coercive control in their relationship
• 29:17 – Their shared violent fantasies and complicity
• 32:10 – The culmination of rage against Becky
• 38:06 – Planning and execution of the abduction
• 40:03 – The psychology of fantasy rehearsal and real-life violence

Conclusion

The episode concludes with the crime in progress: Nathan and Shauna have successfully abducted Becky, and her absence is only just beginning to raise concern. This chilling first part lays bare the psychological littered path that led Nathan Matthews from neglected child to a man capable of orchestrating a horrific crime—his obsessions, abusive relationships, and unresolved rage all converging on a single, tragic target.

Stay tuned for Part 2, where the fallout and investigation are to be explored in-depth.