Prosecutors in Idaho have steadfastly maintained that 23-year-old Andrea Shaw murdered her twin toddlers in the bed they shared, rejecting her claims that they died after adverse reactions to childhood vaccines.

In a court filing Friday, they raised the stakes, saying they will seek the death penalty against her. But the defense team indicated that Shaw would continue with a vaccine injury defense, hiring a lawyer who works with Children’s Health Defense, the anti-vaccine nonprofit founded by the secretary of health and human services, Robert F. Kennedy Jr.

With capital punishment on the table, the Shaw case becomes “a life and death matter for Andrea,” said her new co-counsel, Richard Jaffe, who has made a career of representing physicians he calls “medical mavericks.” But “the case has implications far beyond that,” he said.

In a video statement, Shaw’s other lawyer, Joe Filicetti, said, “There is no chance that a jury is going to find this case beyond a reasonable doubt.”

Shaw’s 18-month-old twins — Dallas, a girl, and Tyson, a boy — died in the family’s mobile home in Payette, Idaho, on May 1, 2025. Shaw was charged with their murder this past June and has pleaded not guilty. The trial is scheduled for January.

In a document filed with the court Monday, the state of Idaho explained its decision, saying that in the double murder, Shaw “exhibited utter disregard for human life.” Mike Duke, the Payette County prosecutor, did not respond to a request for comment.

The case has received widespread attention because it goes to the heart of the national conflict over vaccines and has elicited support from the highest-profile doubters of vaccine safety. Three days after the twins’ deaths, Shaw and her husband, Nathaniel Shaw, appeared on a video podcast produced by Children’s Health Defense.

On camera, Andrea Shaw attributed her children’s deaths to vaccines, describing how, in April 2025, they fell ill after receiving their routine DTaP, flu and hepatitis A shots. At the emergency room the next day, a physician attributed the children’s symptoms of diarrhea, fever and lethargy to “post-immunization reaction,” according to documents obtained by The New York Times from Children’s Health Defense.

Then, in January, five months before her arrest, Shaw became the lead plaintiff in a federal lawsuit filed by Children’s Health Defense against the American Academy of Pediatrics. The suit claims that the nation’s pediatricians defrauded American families by colluding with pharmaceutical makers to spread misinformation about the safety of vaccines.

Children’s Health Defense regards the criminal investigation against Shaw as a “foreseeable consequence of AAP’s fraudulent safety claims,” according to the federal lawsuit. “When the medical system has been told that vaccines cannot cause serious injury or death, grieving parents become suspects rather than victims,” the lawsuit said.

In papers filed last week, Filicetti formally asked the court to accept Jaffe as his co-counsel. Jaffe, who is a member of the bar in California, not in Idaho, is the lead counsel in the Children’s Health Defense case against the pediatricians. He has a history of representing plaintiffs against public health and medical officials.

“Homicide is not really something I’ve done,” Jaffe said. “But I am pretty comfortable with medical issues.”

Duke has argued in court that “this is not a vaccine case.” Shaw came home late from being out with a friend and smothered the twins while her husband slept, Duke has said. According to the filing from his office, her actions meet four statutory conditions for the death penalty, including “exceptional depravity” and “utter disregard for human life.” Further, Shaw probably represents a threat to society, the document said.

A jury must agree on at least one of these conditions beyond a reasonable doubt for her to be sentenced to death. Idaho has not executed a prisoner since 2012. In July, the state made the firing squad its primary method of execution. It tried to put convicted murderer Thomas Creech to death by lethal injection in 2024 but called off the execution after officials failed to find a suitable vein.

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This article originally appeared in The New York Times.

By Lisa Miller/Tony Luong
c. 2026 The New York Times Company