It was the dog days of summer up on Signal Mountain, just outside of Chattanooga, Tennessee when Richard Mason decided to take his son-in-law, Kenneth Griffith, along with Griffith’s military buddy, Earl Smock, out for an ATV ride down to a local swimming hole known as The Blue Hole. Prior to leaving, Manson placed a pistol under the seat of his ATV for protection against any threatening critters that could also be roaming the forests up on the mountain, and the three men set off north down the trail leading to The Blue Hole. It would be the last time the men would be seen alive.


Richard Mason was an expert hunter who knew the forests surrounding his home well. When the men had not returned that night, both Mason’s wife and daughter became worried but had suspected that the men had simply run into some difficulty climbing out of the hole and decided to camp for the night. When none of the men had returned by the following morning, Mason’s family knew that something awful had happened.

On July 10, 1988, Police began combing the trails leading to The Blue Hole, but it would be approximately nine miles east of the area where the men’s ATVs were recovered. Two of the ATVs were found to be covered in blood, but there had been no sign of any bodies and Richard Mason’s pistol remained under the seat.

A massive search party comprised of police and hundreds of local volunteers set out to locate the bodies of the missing men. After an exhaustive multi-day search, an anonymous tip led investigators to the entrance of The Blue Hole known as Helican Gate. Police found pools of blood carefully covered by forest underbrush and the trees had signs that they had been struck by shotgun pellets. While the discovery of a second scene possibly related to the suspected murder of the three men had been a significant break in the case, there were still no bodies to speak of.

It wouldn’t be until a hiker took notice of a particularly foul smell emanating from an illegal trash dump 10 miles west of The Blue Hole, that anyone would know what became of Richard Mason, Kenneth Griffith, or Earl Smock. All of the men had been shot with a pump-action 12g shotgun and all of them had been missing their shoes.


Given the effort the killer had taken to conceal the crime, police suspected that the murderer had been someone local and began interviewing a number of folks who lived up on the mountain.

One possible suspect was Cecil Hickman, a property caretaker who took his job very seriously. Hickman was alleged to have had a run-in with Mason and another friend several months prior to the murder. According to the man who accompanied Mason on the hunting trip, Hickman had shot over the men’s heads after he discovered them trespassing on the property.

Police discovered a 12g shotgun in Hickman’s possession but living in a rural area, it was not unusual for the people who inhabited the mountain to have shotguns for personal protection against aggressive wildlife and to go hunting. Hickman claimed that he had been attending a tractor pull in Kentucky the weekend of the murders and several witnesses, including a preacher, were able to clear Hickman of any wrongdoing.

With no new leads, police had begun to believe that the murders may have been committed by an outsider after all. An anonymous tipster told police that they had spotted a woman in a Chevy Nova near where the ATVs had been dumped nervously blocking the road. According to the caller, there had been a large marijuana grow operation in the area and that it had been their belief that the men may have witnessed a large drug deal going down.

Police were unable to track down the driver of the Chevy Nova, but they did take the time to search the area for evidence of any fields of marijuana. After putting in the time and effort to search through miles of land, only two marijuana plants were found growing. The tip led nowhere and before long the case would grow cold.

It had been over a year since the men had been murdered and police were no closer to cracking the case then the were on the day they started. The television series Unsolved Mysteries reached out to the Mason family and police were hopeful that the nationwide attention was exactly what the case needed.


After the episode aired, investigators were inundated with phone calls and tips related to the case. One caller included the driver of the Chevy Nova, who police still hoped would be an instrumental clue in solving the case for good. The woman explained that she had not initially come forward because her boyfriend had recently been released from prison and they didn’t want investigators to assume that he had been involved. On the night of the murders, the couple’s car had broken down.

While the Chevy Nova tip may have gone nowhere, police would receive another phone call after the episode aired and as they had hoped, it would be a tip that would lead them closer to their killer.

In the cryptic call, investigators were instructed to contact a woman named Marie Hill. Hill was immediately contacted by the police and questioned about her knowledge of the murders. According to Hill, the sordid tale of how she came to know about the murders was a complicated one.

One of the men law enforcement had interviewed during the initial investigation was a man named Frank Casteel. Casteel claimed that he and his wife had been camping near The Blue Hole on a plot of land he had owned during the time of the murders but said he had not heard any gunshots that night. When Casteel had purchased the land surrounding the back end of The Blue Hole, he had considerable trouble keeping people off the property and was instructed to keep a detailed log book of who he had caught trespassing, but there was one slight problem. Some of the property Casteel had claimed as his own was still considered public land and some locals had been chased off by Casteel as far as the Helican Gate.


Casteel had been considered a viable suspect throughout the investigation, but there was simply not enough evidence to bring up charges. Hill confided in the police that she had been having an affair with Casteel for a number of years, but shortly after their relationship had begun, she began to get strange letters claiming that Casteel had committed the murders on Signal Mountain. Hill agreed to have her house bugged so she could confront Casteel about the murders in hopes that they could get a confession on tape.

Shortly after meeting with the police, Hill had invited Casteel over for the evening. Before Casteel could be asked about the murders, Casteel’s wife exploded into the house and confronted Casteel and Hill about the affair. During the argument, Mrs. Casteel began alluding to something she had done for Casteel on the mountain. While the tape wasn’t a formal confession, this in combination with other evidence, including Casteel’s own log book, was enough to bring him up on murder charges.

Casteel was sentenced to three consecutive life terms in 1998, but there are still those who believe in his innocence. In 2001, Casteel was able to overturn his conviction and was granted a new trial. After Casteel’s defense offered the court all of the new evidence they were able to find in favor of Casteel’s innocence, a second jury found him guilty and his sentence was upheld.