Park Predators – "The Ride"

Hosted by Delia D’Ambra
Release Date: September 2, 2025

Episode Overview

In this deeply researched episode, host Delia D’Ambra revisits the haunting Signal Mountain triple murder case from 1988—a crime that shattered a close-knit Tennessee community and left investigators, residents, and the victims’ families searching for answers for decades. Delia’s immersive storytelling weaves personal journeys, archival detail, and community impact, all while exploring the perplexing investigation, the winding path to justice, and the lingering sense of unresolved heartbreak that still surrounds the case.

Key Discussion Points & Timeline

1. Setting the Scene: Signal Mountain, July 1988

[02:00–07:00]

• Signal Mountain: a tight-knit, scenic community in Tennessee, known for its trails and natural beauty.
• The Crime: On July 9, 1988, three men—Kenneth Griffith (22), his friend Earl Smock (24), and Kenneth's father-in-law Richard Mason (49)—went missing after setting out on ATVs to fish at a local swimming spot, the Blue Hole.
• Delia's Personal Connection: She visits the area and involves her husband (a Chattanooga native) in documenting this journey.

2. Disappearance & Immediate Aftermath

[07:01–16:10]

• Saturday Night: The men failed to return; initial family concern gave way to alarm.
• Sunday: Community begins informal searches; a missing persons report is filed.
  • “Neither Martha nor Paula could suppress their gut feeling that something was seriously wrong.” (Delia D’Ambra, 13:50)
• Discovery: ATVs found in a ravine on Roberts Mill Road; two had bloodstains, one had Richard's gun underneath the seat.
  • “ATVs were definitely atypical garbage, even for that spot.” (Delia D’Ambra, 16:10)

3. Crime Scene Details & Investigation

[16:11–22:40]

• Searchers, spurred by the blood on the ATVs, connect the vehicles to the missing men.
• Lead: Reports of gunshots in a wooded section known as “the Helicon.”
• Investigation at Helicon Gate reveals:
  • ATV tracks, spent shells, pools of blood, drag marks, trees marked by pellets, fragments of hair and bone, and human brain tissue.
  • “The Helicon gate was most definitely a crime scene.” (Delia D’Ambra, 20:30)
  • Authorities become nearly certain of foul play: “I’m 98% sure somebody’s dead. ... I’d be willing to stake money that one’s dead. And I’m reasonably sure we’ll find three bodies if we find one.” (Chief Deputy, as quoted by Delia D’Ambra, 21:42)

4. Body Discovery & Multiple Crime Scenes

[22:41–28:30]

• July 13: Bodies discovered 10–12 miles away in a remote illegal dump site, stacked together, shoes removed, all killed by gunfire.
  • Notable detail: “The source material doesn’t mention that any of the shoes were found near or next to the bodies. So that was definitely a strange detail...” (Delia D’Ambra, 26:55)
• Investigators believe the killer(s) tried to scatter the evidence (bodies and ATVs far apart) to obfuscate the true crime scene at Helicon Gate.

5. Theories & Early Suspects

[28:31–34:27]

• Theories considered: Devil worshippers, drug-related ambush, outsiders, or local property disputes.
• Focus turns to two confrontational locals: Cecil Hickman (ruled out via alibi) and Frank Castile, a landowner who regularly confronted trespassers.
• Castile’s interactions with police: Calm, cooperative, offered up his logbook and firearms.
• Ballistics on shells unclear; connection to the murder weapon is inconclusive.

6. Case Goes Cold & Community Impact

[34:28–39:55]

• With no clear evidence, no arrests are made—case goes cold for nearly a decade.
• Frank Castile becomes a pariah in the community due to suspicion, but remains uncharged.
• Community and family are left in limbo.
  • “Justice had not been served, and he felt sorry for Kenneth, Earle and Richard’s families because he wasn’t convinced that his father was the person responsible for the three men’s deaths.” (Paraphrased from Trevor Castile, 47:55)

7. Breakthrough & Arrest (Mid-1990s)

[39:56–44:26]

• In 1996, an anonymous tip leads to Marie Hill, who’d been in a relationship with Frank Castile.
• Anonymous letters accusing Frank; DNA reveals Frank’s wife, Susie, authored them to scare off Hill.
• Despite twists, surveillance and wiretaps fail to capture confessions, but Frank is charged in 1997 with triple homicide.

8. Trials and Appeals

[44:27–50:45]

• First Trial (1998): Prosecution presents Castile as a property-obsessed, intimidating presence. Key evidence: negative prior confrontations; the wiretapped tapes; suspicious timeline.

• Witnesses: Several testify to Castile’s aggression toward trespassers. His wife and mistress both take the stand.

  • “His lawyer said that Frank's rebuttal to all of the witnesses...was that they were all lying and he was the only person telling the truth.” (Delia D’Ambra, 49:02)

• Defense: Castile takes the stand and denies involvement; jury is unconvinced.

• Verdict: Guilty, sentenced to life with parole possibility after 51 years.

  • Kenneth’s brother, Lee: “The verdict was kind of like a salve to a wound that will never be healed. ... We’ll always miss Kenneth. We had dreams of retiring together and watching our kids grow old. It was all taken away from us.” (Lee Griffith, Associated Press, 50:27)

• Second Trial (2003): Conviction overturned on appeal (improper admission of circumstantial evidence); new defense witness tries to implicate others, but Castile is again found guilty.

9. Aftermath & Reflection

[50:46–51:35]

• Castile dies in prison in 2019.
• Impact on the families: Profound emotional toll, persistent lack of closure.
  • Lee Griffith: “It was like being in a movie that you couldn’t turn off. We don’t have to devote any more of our lives to this.” (Lee, WTVC, 51:10)
• Delia’s closing thoughts: Laments the tragic loss, the randomness of violence, and the lasting wounds on all involved. Encourages listeners to remember the victims and the unpredictability of tragedy in the most beautiful places.

Notable Quotes & Moments

• [13:50] Delia D’Ambra:
  “Neither Martha nor Paula could suppress their gut feeling that something was seriously wrong.”

• [20:30] Delia D’Ambra:
  “The Helicon gate was most definitely a crime scene.”

• [21:42] Chief Deputy (via Delia):
  “I’m 98% sure somebody’s dead. ... I’d be willing to stake money that one’s dead. And I’m reasonably sure we’ll find three bodies if we find one.”

• [26:55] Delia D’Ambra:
  “The source material doesn’t mention that any of the shoes were found near or next to the bodies. So that was definitely a strange detail...”

• [49:02] Delia D’Ambra (on Frank’s defense):
  “His lawyer said that Frank's rebuttal to all of the witnesses...was that they were all lying and he was the only person telling the truth.”

• [50:27] Lee Griffith:
  “The verdict was kind of like a salve to a wound that will never be healed. ... We’ll always miss Kenneth. We had dreams of retiring together and watching our kids grow old. It was all taken away from us.”

• [51:10] Lee Griffith (on Castile’s death):
  “It was like being in a movie that you couldn’t turn off. We don’t have to devote any more of our lives to this.”

Episode Structure & Tone

• Tone: Investigative, empathetic, and contemplative, blending Delia’s meticulous research with her respect for the victims and their families.
• Style: Richly narrative with a balance of factual detail and personal reflection—true to Delia’s hallmark style on "Park Predators."
• Flow: Moves chronologically, weaving personal stories with methodical breakdowns of each investigative phase.

Conclusion

Delia closes by reflecting on the randomness and senselessness of the Signal Mountain murders, the fractured lives left in their wake, and the reminder that even in the most beautiful places, darkness may lurk. She encourages listeners to honor the memories of Kenneth Griffith, Earl Smock, and Richard Mason and to never take a simple ride in nature for granted.

For further reading and sources, visit: parkpredators.com
Follow the show: Instagram @parkpredators