Serial Killer: Jason Thornburg
David Lueras, Lauren Phillips, Maricruz Mathis, Mark Jewell & Tanya Begay
David Lueras was 42 years old and shared a motel room with Jason Thornburg at the Mid City Inn in Euless, Texas, where Thornburg had been staying since around July 2021. Lueras was the first of the three Fort Worth victims killed. At Thornburg's sentencing, Lueras's sister told the court that he took her brother's life in horrific and unspeakable acts, and his mother, Mary Boydstun, spoke on behalf of all the families about the justice they had waited years to receive.
Lauren Phillips was 34 years old. According to Thornburg's own statements to police, he knew her only casually before killing her at the same motel within days of Lueras's death.
Maricruz Mathis, also referred to as Maricruz Reyes-Mathis in some records, was 33 years old. Like Lauren, Thornburg told police he knew her only casually before killing her at the motel in the same week as the other two victims.
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Mark Jewell was 61 years old and was Thornburg's roommate at a home in Fort Worth. He was killed in May 2021, months before the Fort Worth motel murders. Thornburg later spoke at Jewell's funeral without anyone suspecting his involvement in Jewell's death.
Tanya Begay was a Navajo woman from Gallup, New Mexico, and Thornburg's girlfriend at the time of her disappearance. In March 2017, she told her mother she planned to travel from Leupp, Arizona, back to her family's home near Gallup, a drive through the Navajo Nation, while traveling with Thornburg. She was never seen again. Her body has never been recovered, and Thornburg has not been charged in connection with her death.
Four Years, Five Victims, Two States
In March 2017, Tanya Begay disappeared while traveling through the Navajo Nation with her boyfriend, Jason Thornburg, on a drive from Leupp, Arizona, toward her family's home near Gallup, New Mexico. She was reported missing to New Mexico police, and her body has never been recovered. Thornburg later confessed to killing her but was never charged in her death due to insufficient evidence.
In May 2021, Thornburg killed his roommate, Mark Jewell, 61, at a home in Fort Worth, Texas. Thornburg later admitted to slitting Jewell's throat, then uncapping a natural gas line and lighting a candle, causing the house to catch fire and explode. Thornburg reportedly spoke at Jewell's funeral without anyone suspecting his involvement.
By July 2021, Thornburg, an electrician's apprentice, was renting a room at the Mid City Inn in Euless, a Fort Worth suburb. Over roughly a week in September 2021, Thornburg brought three people he knew to his motel room separately and killed each of them. He told investigators he believed David Lueras, Lauren Phillips, and Maricruz Mathis each needed to be sacrificed for religious reasons.
According to Thornburg's own statements to police, he slit the throat of David Lueras, 42, who shared his motel room, then dismembered his body in the bathtub; he also admitted to eating part of Lueras's heart and cutting off his genitals. Two days later, he strangled Lauren Phillips, 34, sexually assaulted her body after death, and dismembered her as well. He then killed Maricruz Mathis, 33, by slitting her throat and dismembering her body in the same manner. Thornburg stored the dismembered remains in trash bags and later in plastic storage bins inside the motel room for several days.
On the night of September 21, 2021, surveillance footage captured an SUV arriving at a dumpster in the 3100 block of Bonnie Drive in Fort Worth, where someone unloaded containers; the vehicle returned early the next morning to deposit more. In the early morning hours of September 22, the dumpster was found engulfed in flames, and the burned, dismembered remains of Lueras, Phillips, and Mathis were discovered inside.
From Disappearance to Death Sentence
Connecting Four Crime Scenes
Fort Worth police used surveillance footage from the Mid City Inn motel and from cameras near the dumpster on Bonnie Drive to identify the SUV used to transport the remains, ultimately tracing it back to Thornburg. Investigators also connected Thornburg to the earlier death of his roommate, Mark Jewell, through matching vehicle registration, a link that helped narrow the suspect list in the Fort Worth case even before the connection between the two cases was publicly known.
During questioning, Thornburg confessed in detail to all three Fort Worth killings as well as the earlier deaths of Jewell and Begay, providing investigators with an account of his methods and motivations that formed the basis of both the capital murder indictment and the separate charges in Jewell's death.
Case documents:
Jason Alan Thornburg
Jason Thornburg was convicted of the capital murders of David Lueras, Lauren Phillips, and Maricruz Mathis and sentenced to death. He has also confessed to killing his roommate, Mark Jewell, and his former girlfriend, Tanya Begay, though the status of the Jewell prosecution following Thornburg's death sentence is unclear as of the most recent reporting, and he has never been charged in Begay's death, as her body has never been recovered.
Thornburg was born in Cerritos, California, and worked as an electrician's apprentice. He described his purpose in life as serving God and expressed a wish to become a missionary, a stated self-image sharply at odds with the killings he confessed to committing. No documented criminal record predates the 2017 killing of Tanya Begay in the reporting reviewed for this page.
Detailed information about Thornburg's childhood, family history, upbringing, or any documented mental health history is not established in independently verified reporting available for this page. This is a genuine gap in the public record rather than an indication that no such history exists.
This is documented background, not an explanation for Thornburg's crimes. Given how limited the available record is, this page cannot offer meaningful insight into contributing factors in his case, and none should be inferred beyond what is stated here.
Context Around This Case
David, Lauren, Maricruz, Mark & Tanya
David Lueras, Lauren Phillips, and Maricruz Mathis were people who crossed paths with the same man at the same motel over the course of a single terrible week. Mark Jewell trusted his roommate enough to share a home with him. Tanya Begay loved someone who took her from her family on a road trip she never came home from, and to this day her family has no place to grieve her, only the unbearable weight of not knowing. At sentencing, David's family spoke on behalf of them all: that it was right to grieve, and right to demand and receive justice, for the taking of these lives and for how their bodies were treated afterward. Five people, connected only by the same man's violence, are remembered here, together, as the people they were before any of this happened to them.