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Signal Mountain murders

SOLVED2001Signal Mountain area near Suck Creek, Chattanooga, Tennessee3 SOURCESUPDATED JUL 2026
Illustrative

In 1988, Richard Mason, his son-in-law Kenneth Griffith, and Earl Smock were riding all-terrain vehicles (ATVs) through the backwoods of Signal Mountain near Chattanooga, Tennessee. When the three men did not return home, relatives reported them missing and a search began. Their bodies were subsequently found off Big Fork Road near the community of Suck Creek by a resident, while their ATVs were located down an embankment on the side of Roberts Mill Road.

The land where the men had been riding was owned by Frank Casteel's family. According to accounts described in the case history, Casteel had grown increasingly frustrated with people trespassing on the property. After noticing a rise in intrusions, he consulted a police officer, who advised him to keep a logbook documenting everyone he observed on the land. Multiple witnesses later recalled Casteel making statements about his frustration with trespassers, including that he "would kill if he had to." Following the discovery of the three bodies, Casteel became a suspect.

Casteel was convicted in 1998 of three counts of first-degree murder and was sentenced to life in prison. In 2001, the Tennessee Court of Criminal Appeals overturned the convictions and ordered a new trial because portions of recorded conversations should not have been played to the jury. In 2003, Casteel was retried and again convicted of the three murders, and he returned to prison.

Casteel died in prison in May 2019 at the age of 71.

The case received significant media attention over the years. Unsolved Mysteries aired a segment on the killings in a season 2 episode that first broadcast on January 3, 1990. A&E's City Confidential series covered the case in a season 3 episode titled "Dangerous Trespassing." Investigation Discovery also portrayed the murders in an episode of its series "Bloodlands," titled "Signal Mountain Murders," which aired on August 18, 2014.

Key facts

Victims
Earl Smock, Richard Mason, Kenneth Griffith
Date
2001
Location
Signal Mountain area near Suck Creek, Chattanooga, Tennessee
Case status
solved

Case timeline

  1. 1988

    Richard Mason, Kenneth Griffith, and Earl Smock go missing while riding ATVs on Signal Mountain near Chattanooga, Tennessee; their bodies are later found off Big Fork Road near Suck Creek, with their ATVs found down an embankment on Roberts Mill Road.

  2. 1988

    Larry Sneed takes possession of a logbook kept by Frank Casteel documenting trespassers on his land.

  3. 2001

    Frank Casteel is given an opportunity to overturn his conviction on appeal.

  4. 2003

    Frank Casteel is found guilty again of the triple homicide and returned to prison.

  5. 2019-05

    Frank Casteel dies in prison at age 71.

  6. 2020

    Casteel's son, Franklin Trever Casteel, authors a book on the case.

  7. 1990-01-03

    Unsolved Mysteries airs a segment on the case (season 2, episode 13).

  8. 2014-08-18

    Investigation Discovery airs an episode on the case in its series 'Bloodlands' (season 1, episode 3).

Best coverage

No approved coverage links are attached yet.

People

  • Earl Smock

    VICTIM

    Killed in 1988 while riding ATVs on Signal Mountain.

  • Richard Mason

    VICTIM

    Killed in 1988 while riding ATVs on Signal Mountain near Chattanooga, Tennessee.

  • Frank Casteel

    CONVICTED

    Landowner convicted of the triple homicide; sentenced to life in prison, had conviction overturned in 2001, reconvicted in 2003, died in prison in May 2019.

  • Kenneth Griffith

    VICTIM

    Son-in-law of Richard Mason; killed in 1988 while riding ATVs on Signal Mountain.

Roles reflect public records and court outcomes at the time of writing — supporting citations are on file under Sources.

Places

Signal Mountain area near Suck Creek, Chattanooga, Tennessee

35.1495, -85.3419

View on the map

Common questions

What happened to the victim?
In 1988, three men riding ATVs on Signal Mountain near Chattanooga, Tennessee — Richard Mason, his son-in-law Kenneth Griffith, and Earl Smock — were found shot to death after being reported missing. Landowner Frank Casteel was convicted of the triple homicide, had the conviction overturned on appeal in 2001, was reconvicted in 2003, and died in prison in May 2019.
Where did the murders happen?
Signal Mountain area near Suck Creek, Chattanooga, Tennessee.
Who was convicted?
Frank Casteel (Landowner convicted of the triple homicide; sentenced to life in prison, had conviction overturned in 2001, reconvicted in 2003, died in prison in May 2019.).
What is the current status of the case?
Status: solved.
More cases in Tennessee

Sources

  1. ENCYCLOPEDICSignal Mountain murdersWikipedia · 2026-07-10
  2. PRESSSignal Mountain Murder Case Featuredchattanoogan.com · 2026-07-10
  3. PRESSFrank Casteel, convicted of 1988 Signal Mountain murders, dies in prisonnewschannel9.com · 2026-07-10