Martin Dean Priest: Convicted Murderer and Suspected Serial Killer
Overview
Martin Dean Priest is an American murderer whose criminal history stretches across Missouri and Kansas during the 1980s. He was convicted of killing William H. Mayhugh in Wichita, Kansas, and decades later was convicted of murdering Missouri teenager Tammy Sue Rothganger. Priest was also prosecuted, but ultimately acquitted, in the deaths of Tonya Lea Lewis, Katrina Cheely and Frieda Bayliff.
The cases associated with Priest involved teenage girls, acquaintances and people connected to women with whom he had relationships. Several victims disappeared after accepting rides from him or after being seen in his company. Priest repeatedly gave investigators conflicting explanations, attempted to influence witnesses and, according to testimony, used threats and manipulation to conceal what had happened.
Because Priest was acquitted in three of the cases, he cannot legally be described as having been convicted of those killings. However, investigators continued to regard him as a suspect, and the similarities between the disappearances, his access to the victims and later witness statements caused authorities to investigate him as a possible serial killer.
Victims and Suspected Victims
- Tonya Lea Lewis — approximately June 13, 1980 — Vernon County, Missouri: Tonya was a 12-year-old student from Nevada, Missouri. She disappeared after spending time with Priest, who had been working with a painting crew at her family’s residence. Her body was found on June 15, 1980, floating in a farm pond approximately 11 miles south of Nevada. Investigators believed she had died about two days earlier. Her death was attributed to drowning, although there were no obvious external wounds. Priest was convicted of her murder in 1981, but the conviction was later overturned. At a retrial in 1983, he was acquitted because prosecutors could not conclusively prove that Tonya’s drowning was a homicide rather than an accident.
- Tammy Sue Rothganger — May 16, 1984 — Eldon, Missouri: Tammy was 15 years old when she disappeared while going to school. Witnesses saw her enter a blue Plymouth occupied by Priest and his 13-year-old nephew, David Nicholas. More than 30 years later, Nicholas testified that Priest drove Tammy to a remote area, struck her with a wrench, raped her and strangled her. Nicholas said Priest concealed the body and later moved it to another location. Tammy’s remains have never been recovered. Priest was convicted of her murder in 2016 and received another life sentence.
- Katrina Cheely — believed killed on or shortly after November 16, 1984 — Wichita, Kansas: Katrina was a teenage student who disappeared after Priest offered to drive her to school. She never attended classes that day. Her partially decomposed body was discovered in a drainage culvert on February 28, 1985. She had been left without clothing, and investigators determined that she had died from asphyxiation, although accounts of the medical findings have varied. Priest’s former wife later said he gave her a bracelet belonging to Katrina and claimed that he had attempted to molest Katrina before strangling her with her pantyhose. Priest was tried for the killing in 1987 but was acquitted.
- William H. Mayhugh — approximately December 25, 1984 — Wichita, Kansas: Mayhugh was 25 years old and lived with Frieda Bayliff. He was last known to be alive around Christmas. His body was discovered on December 27, 1984, in a ditch near the Arkansas River and a Wichita flood-control channel. He had been shot once in the head. Priest knew Mayhugh and Bayliff through a Wichita bar frequented by the couple. Priest was convicted of Mayhugh’s murder and sentenced to life imprisonment in Kansas.
- Frieda Bayliff — approximately December 25, 1984 — Wichita, Kansas: Bayliff, 33, was found dead on December 28, 1984, inside the residence she shared with William Mayhugh. She had been strangled. The couple had last been seen by relatives around Christmas, and investigators believed their deaths were connected. Priest was charged with Bayliff’s murder but was acquitted, even though he was convicted in the related killing of Mayhugh.
The Death of Tonya Lea Lewis
In June 1980, Priest was working as part of a painting crew at the Lewis family’s residence in Nevada, Missouri. While inside the home, he reportedly overheard Tonya discussing plans with a friend. Priest then left the painting job after claiming that he needed to attend a job interview.
Tonya was subsequently seen spending time with Priest. When she failed to return home, her mother questioned him about the girl’s whereabouts. Priest claimed that they had played basketball and that he later went home. Two days after Tonya disappeared, fishermen discovered her body in a rural farm pond.
The absence of obvious physical injuries complicated the investigation. Authorities eventually treated the drowning as a homicide and arrested Priest. In March 1981, a jury convicted him, and he was sentenced to 25 years in prison. Priest continued challenging the verdict, arguing that the state had failed to establish that Tonya had been intentionally killed.
Priest eventually received a new trial. Because the medical evidence could not conclusively exclude accidental drowning, he was acquitted in 1983 and released. Although the acquittal ended the prosecution, investigators continued to view the circumstances of Tonya’s disappearance and death as suspicious.
The Murder of Tammy Sue Rothganger
After his release, Priest began a relationship with Tammy Rothganger’s mother in Eldon, Missouri. On the morning of May 16, 1984, Tammy left for school. Friends saw her near the school at approximately 7:45 a.m., but she never attended class. Another student saw her enter a vehicle containing Priest and his young nephew, David Nicholas.
Priest later offered inconsistent accounts of his actions. He claimed that Tammy planned to skip school and that he dropped her off at Rock Island Park to meet friends. Those friends denied making any such plans. Tammy was never seen alive again, and her body was not found.
The case remained unresolved for decades. Nicholas eventually approached investigators and described what he said had happened inside Priest’s car. According to his testimony, Priest drove Tammy to an isolated location despite her repeated requests to return to school. Tammy attempted to flee, but Nicholas, acting under Priest’s direction, persuaded her to return.
Nicholas testified that Priest pressured the two teenagers into sexual activity while he watched. Priest then ordered Tammy into the front seat, struck her in the head with a wrench, raped her and strangled her. When Nicholas tried to interfere, Priest struck and threatened him. Priest allegedly warned the boy that he would also be blamed for the crime and that the same thing could happen to him if he spoke to anyone.
According to the testimony, Priest concealed Tammy’s body and later moved it. Nicholas attempted to help investigators locate the burial site, but Tammy’s remains were never recovered. Other evidence showed that Priest had asked a former girlfriend to provide a false account of seeing Tammy after her disappearance. He also reportedly told Tammy’s mother that he had hidden the girl and that she would have to remain with him if she ever wanted to see her daughter again.
Priest was charged in 2016 and convicted of first-degree murder. The conviction was based largely on Nicholas’s eyewitness testimony, corroborating witness accounts and evidence of Priest’s attempts to deceive Tammy’s family and investigators. His conviction was upheld by the Missouri Court of Appeals in 2019.
The Disappearance and Death of Katrina Cheely
After Tammy disappeared, Priest relocated to Wichita, Kansas. He became involved with Katrina Cheely’s mother and was present at the family’s home on November 16, 1984, when Katrina was preparing for school. Priest offered to drive her because she was running late.
Katrina never arrived at school. Priest claimed that he had dropped her off, but no reliable evidence confirmed his story. Her disappearance closely resembled Tammy’s case: both girls were teenagers, both were going to school and both vanished after entering a vehicle with Priest.
On February 28, 1985, a man investigating an area where his dog had repeatedly barked discovered Katrina’s body in a culvert. Her remains were identified through personal property, including a schoolbook and jewelry. Investigators believed she had been asphyxiated.
Priest’s former wife, Debra Yoder, later told authorities that Priest had given her Katrina’s bracelet as a birthday present. She also said Priest admitted trying to molest Katrina and strangling her after she resisted. This information led to Priest being charged with Katrina’s murder.
Despite the testimony and the possession of Katrina’s property, the jury acquitted Priest in December 1987. The acquittal meant he could not be retried for the same offense, although investigators continued to identify him as the principal suspect.
The Wichita Double-Homicide Investigation
During Christmas week in 1984, William Mayhugh and Frieda Bayliff disappeared from contact with relatives. On December 27, Mayhugh’s body was found in a ditch near Wichita’s flood-control system. He had been shot in the head.
The following day, Bayliff was discovered strangled inside the home she shared with Mayhugh. The timing, the victims’ relationship and the differing methods of killing led investigators to consider the deaths part of the same criminal episode.
Priest had met the couple through Bayliff, who worked as a waitress at a Wichita bar. Prosecutors charged him in connection with both killings. A jury convicted him of murdering Mayhugh but acquitted him of killing Bayliff. Priest received a mandatory life sentence for Mayhugh’s murder and was incarcerated within the Kansas correctional system.
Arrest and Investigative Pattern
Priest was arrested on March 30, 1985, after investigators connected him to the Wichita killings. At the time, he had already been accused and acquitted in Tonya Lewis’s death and was associated with two missing teenage girls.
Several recurring elements appeared in the cases. Priest developed relationships with women who had teenage daughters, gained the trust of those families and placed himself in a position where he could be alone with the girls. Both Tammy Rothganger and Katrina Cheely disappeared while traveling to school, and witnesses placed Priest in the vehicle with each girl.
Priest also attempted to control the narrative after victims vanished. He supplied explanations that conflicted with witness accounts, encouraged others to lie and allegedly used threats to silence people who knew what had happened. In Tammy’s case, the eyewitness was a frightened 13-year-old relative whom Priest manipulated into believing that he would be punished as an accomplice.
Convictions, Acquittals and Imprisonment
Priest’s criminal record is unusual because it includes both murder convictions and murder acquittals. His original conviction for Tonya Lewis’s death was overturned, and he was acquitted at a second trial. He was later acquitted of killing Katrina Cheely and Frieda Bayliff.
He was successfully convicted of murdering William Mayhugh in Kansas and Tammy Rothganger in Missouri. Those two convictions resulted in life sentences. The Tammy Rothganger verdict was especially significant because it resolved a disappearance that had remained officially unsolved for more than three decades, even though her body was never located.
Martin Dean Priest remains known as a convicted double murderer and suspected serial killer. The confirmed convictions establish that he killed at least two people, while the additional deaths and disappearances associated with him suggest that his complete number of victims may have been higher. The acquittals in the other cases must be recognized, but the evidence surrounding those victims has continued to make Priest a central figure in their histories.
