Details revealed in gruesome triple-murder trial, Jason Thornburg sentenced to death

FORT WORTH, Texas - A Tarrant County jury decided to sentence a 44-year-old man to death after he was convicted of the gruesome murders of three people and setting their remains on fire in 2021. During the weeks-long trial, new information was revealed about what happened in the seven days at the Euless motel leading up to the dumpster fire in Fort Worth.

Because of the evidence presented during the trial, the jury decided Thornburg was considered a future danger and sentenced him to death.          

Details Revealed During Trial

In September 2021, Jason Thurnburg said David Lueras, 42, Maricruz Mathis, 33, and Lauren Phillips, 34, needed to be sacrificed for religious reasons. 

Over seven days at the Mid City Inn in Euless, Thornburg brought each of them, separately, into the room he was renting. He slit the throats of Lueras and Mathis. He strangled Phillips and sexually assaulted her corpse. He ate some of David's heart and cut off his penis. 

Once they were dead, he cut their bodies into pieces in the motel bathtub, then stored their remains in trash bags under his bed. 

Early in the morning on September 22, 2021, Thornburg took their body parts, now in plastic storage tubs, to a dumpster on Bonnie Drive in Fort Worth. Once all the remains were in the dumpster, Thornburg set them on fire and drove away. 

He cleaned out and returned the tubs to the store where they were bought. 

Firefighters responded to the dumpster fire, extinguished it, and police tracked down Thornburg as the person who put the remains in the dumpster and burned them based on a video that captured his Jeep Grand Cherokee in the area at the time of the dumpster fire.

When Thornburg was arrested for the 2021 motel murders, he reportedly confessed to police he killed both his roommate in May 2021 during a suspicious home explosion and his girlfriend Tanya Begay in Arizona back in 2017.

Thornburg was indicted in the killing of his roommate, 61-year-old Mark Jewell. Jewell's body was found by firefighters after a gas explosion at their Fort Worth home in May 2021.

Tanya vanished in March 2017. The missing indigenous woman was last seen with her then-boyfriend Jason Alan Thornburg. Thornburg allegedly told detectives that he sacrificed Begay in Arizona. The FBI considers Tanya's case open, and her body has not been found. 

Closing Statements to the Jury

The Prosecution

During the prosecution's closing statements, the prosecution addressed the jury for about 12 minutes. 

"He is a psychopath. He is evil. He is the type of evil that we want to believe doesn't exist in our community. We want to believe we are not raising our children in a world where people like Jason Thornburg exist. We want to believe we live in a world where the Bible is not a weapon, where your vulnerabilities don't make you prey to a serial killer. But so long as we live in a world with Jason Thornburg, said evil will exist."

The prosecution said during the trial, the defense said Thornburg's executive functions did not work. The attorney said he has a long history of employment as an electrician and a 4.0 at a community college. 

"You don't almost get away with two murders with a lack of executive functioning."

The prosecution said, "If you need examples of his executive functioning working just fine, we'll listen to his statement again."

Here are the statements the prosecution says Thornburg has made: 

"I couldn’t use my chainsaw because that would be too loud, and I would get caught. I have to use my knife. I can't carry out the bodies like that. That would be too obvious. I need to get my car back. I need to go buy some bins and load them up in my car. I need to go dump these bodies in a dumpster 30 miles away to distance myself from the crime. I need to light the bodies on fire because I've done it twice before, and I know that works, and I need to destroy the fingerprints."

The Defense

Thornburg's defense attorneys then each gave a closing argument.

They began by saying Jason Thorburg was "doomed in the womb," saying he had no chance to "be the correct person he should be. He didn't choose to be that way."

The defense asked if Thornburg told the police officers the truth. "Yes, he did. Because he thought he did the right thing by committing a horrible sinful sacrifice. It's the voices he heard which are not justified. They are evil in a way, but he believed it was correct. That is so bizarre. So bizarre. But see, that's what he believed. He believed his sacrifices were correct, and we know, as citizens, it's not correct."

The second defense attorney stated:

"You have to decide as jurors, do we execute someone who is psychotic at the time they did something? You have to ask yourself, do we execute someone who is delusional? Is that what we're about as a civilized society? Do we execute someone whose mother left them in a position where they were susceptible to all of the evils in our society? Do we do that as a civilized society? Or do we take the other option and confine them for the remainder of their natural life?We lock them up and throw away the key and bury them under the courthouse. Which is the more just thing to do? Is it more just when someone responds to medication and stops seeing hallucinations? And the psychosis is severely reduced? Is it just to execute that person or is it just a thing to continue with the regiment that they're on? It has changed their life."

The Prosecution Rebuttal

When the prosecution presented a rebuttal, she said: "We don't use words like cannibal, because it's fun. We use words like cannibal because he ate David's heart. We don't use the word sadist because it is a buzz word, we use sadist because (Thornburg) had sex with Lauren's torso. And he cut off David's penis. And he raped Alicia Woods. And we all know what he did to Alicia, is exactly what he did to Maricruz and Lauren. We use the word sadist because he's the kind of person who would have sex with Lauren with the bodies of Maricruz and David underneath that bed. He can be aroused in a moment where there are two bodies under his bed."

She continued, "This is not about death. This is not about theoretical cannibals. This is about a man who took the heart of the man right there and put it in his mouth. That's why we're here. And ladies and gentlemen, remember we sat here and talked about, ‘oh the ritual.’ See, ladies and gentlemen, the reason he did all of this, is the ritual. And the fire, the ‘fire cleanses his soul.’ No. The fire cleanses crime scenes. And now you know that, because you know about Tanya now. You know that in 2017, not because of a ritual, not because God told him to, but because he regularly beat this woman in a domestic violence situation that resulted in him throwing a coffee pot in her eye. And when he's about to get in trouble for that, she goes missing. And we know, now, that he burned her. He used the word cremated. Do you know how long you have to burn someone to cremate? That's what he did. Because fire, once again, cleansed his crime scene."

The Sentencing

It took the jury less than five hours to decide Jason Thornburg was a future danger. He didn't show any emotion as the sentence was read. The decision was unanimous, and the jurors were polled. 

The judge said, "Therefore, Jason Allen Thornburg. You have been adjudged by a jury to be guilty of capital murder. And the juror has answered the special issues making it mandatory that your punishment be death. Therefore, this court sentences you, Jason Allen Thornburgh, to death."

The court clerk has 10 days from Dec. 4, 2024 to enter the order, setting the date for execution. 

He continued, "This sentence shall be executed at any time after the hour of 6 p.m. on the day set for the execution. By intravenous injection of a substance or substances in a lethal quantity sufficient to cause death, and until you, Jason Allen Thornburg, are dead."

The judgment of conviction and sentence of death are subject to automatic review by the Court of Criminal Appeals. 

Thornburg will stay in the custody of the state until his death sentence is carried out, which could be several years away. 

Victim Impact Statements

Families of the victims faced Thornburg in court, comparing him to Satan and calling him evil and a coward. They did not hold back when it was time for them to speak. 

"I do believe, and it is my opinion, that you are a danger to society, and the only thing you do deserve is death, like our loved ones," said Maricruz Mathis' sister. "Jason Thornburg, I hope that you receive forgiveness in Heaven, because personally I don’t think I can do it." 

Lauren Phillips' aunt told him, "Yeah you're a coward. You can't face man on man and show you're true nature. Instead, you prey on the vulnerable. Yes, you’re exactly like Satan. A liar, thief and a murdering coward." 

David Lueras' sister told the court, "He took the life of our loved one in horrific and unspeakable acts which in it of themselves are evil."

Although Thornburg was not convicted for the death of Tanya Begay, a family member was allowed to speak during the victim impact statements. They said, "The pain of this loss is overwhelming every day because we still don’t know where she is." 

David Lueras' mother, Mary Boydstun, read a statement on behalf of all the families. She said, "Today it is right that we grieve their deaths, it is right that we demand and we receive justice. For the taking of their lives and the way their bodies were treated."

She shared that their faith has kept them strong throughout the trial. 

"Our constant source of our strength all this time has been from our Heavenly Father," she said. 

"Tanya Begay, Mark Jewell, Lauren Phillips, Maricruz Mathis and David Lueras, are prodigals have been home with Jesus, and we have all received justice on their behalf. Thank you." 

Tarrant CountyEulessFort WorthCrime and Public Safety