An Idaho mother who said her 18-month-old twins died last year after receiving three vaccines has been charged with murder in their deaths, officials said last week.

Andrea Shaw, 23, was indicted on two counts of first-degree murder in the deaths of her toddlers, Tyson and Dallas, who were found dead in a shared bed on 1 May last year.

Police officers responded to the home in Payette, Idaho, after receiving a report of a possibly deceased child.

“Upon arrival, officers discovered two deceased children, twin siblings, in a shared bed,” Payette police said at the time, adding that the case was being investigated as a homicide.

Investigators initially did not identify the mother of the children and said the investigation was ongoing while the cause of death was to be determined by the Ada county medical examiner’s office.

More than a year later, the cause of death has not been publicly released.

Days after her twins died, Shaw and her husband appeared on a podcast produced by the anti-vaccination organization Children’s Health Defense, which was previously led by Donald Trump’s health and human services secretary, Robert F Kennedy Jr, with Shaw claiming that vaccines had killed her children.

She told the podcast she was being looked at as a suspect. “So, the way they worded it to me, especially on the second day of interrogation, [was] they said that it wasn’t medical and that they determined asphyxiation. And that I had supposedly had a postpartum overwhelming blackout and done it to my children,” Shaw said.

In a GiveSendGo fundraiser linked to the episode, the family said they had taken the twins to their 18-month well-child visit, where they received routine vaccines, and alleged that both babies died in their sleep a few days later.

That fundraiser raised more than $10,000.

Shaw’s attorney, Joseph Filicetti, also alleged to the Boise station KTVB that the twins had died from vaccinations.

“They were looking at it as a vaccine death, and that’s still what I believe it to be,” Filicetti said. “I’m not a medical expert, but the medical experts I have, they go through a series of steps when looking at different complications.”

Filicetti did not provide KTVB with any evidence to support these claims when prompted.

Shaw was arrested without incident in Boise on 30 June. She is being held on a $2m bond.

Citing court documents, KTVB reported that the indictment alleges that Shaw suffocated her toddlers. Shaw’s civil lawsuit against the American Academy of Pediatrics, filed with Children’s Health Defense, said no alternative cause of death had been identified for either child.

Payette police said last Tuesday that because the case was now before the court, they would have no further comment regarding the facts of the case or the evidence, and that future information would come only through the judicial process.

Shaw’s next appearance in Payette county district court is scheduled for 14 July.