Mark Jewell, a 61-year-old white male from Euless, Texas, was found dead on May 21, 2021, following a devastating explosion at the Fort Worth home he shared with his roommate, Jason Alan Thornburg. Initially, the Tarrant County Medical Examiner listed Jewell’s cause of death as “thermal and blast injuries,” due to the severity of the explosion. However, the manner of death was later amended to homicide after Thornburg confessed to killing Jewell during a police interview.
Thornburg admitted to slitting Jewell’s throat, uncapping a natural gas line, and lighting a candle before leaving for work, which led to the fatal explosion.
Jason Thornburg, a 41-year-old male, was indicted for murder and arson in connection with Jewell’s death. These charges are first-degree felonies and carry a potential sentence of life in prison. Thornburg’s arrest came after he was already under investigation for a separate triple homicide that occurred in September 2021. In that case, the dismembered bodies of David Lueras Lauren Phillips and Maricruz Reyes-Mathis were discovered burning in a dumpster in Fort Worth. Surveillance footage and forensic evidence linked Thornburg to the crime scene, and he later confessed to all three murders.
During questioning, Thornburg revealed disturbing motivations behind his actions, claiming he had an “in-depth knowledge of the Bible” and believed he was called to perform human sacrifices. He described Jewell’s murder as one such “sacrifice.” Thornburg also admitted to killing his girlfriend, Tanya Begay, a Navajo woman from Gallup, New Mexico, in 2017, although her body has never been recovered and he has not been charged in her death.
Thornburg’s mental health became a point of concern during legal proceedings. A magistrate judge ordered a mental health evaluation, citing reasonable cause to believe Thornburg might suffer from mental illness or intellectual disability. Despite his defense team’s argument for an insanity plea, the jury ultimately found his actions to be deliberate and premeditated. Thornburg was sentenced to death for the triple homicide, and his conviction in Jewell’s murder further solidified his status as one of Fort Worth’s most notorious killers.
