The father of four children poisoned to death by their mother and grandmother in a harrowing murder-suicide is now seeking $400 million from upstate New York government and school agencies – whom he claims failed to protect the kids from years of abuse, bombshell court documents reveal. 

Brady Harmon filed a legal notice announcing his intentions to sue the City of Mechanicville, Saratoga County, two school districts and a housing authority over allegations of negligence and systemic failures – three months to the day after authorities say his ex-wife and her mother conspired to fatally poison the kids and themselves on June 10. 

The children – Harper, 13; Hudson, 11, and 10-year-old twins Gracelynn and Gavin Harmon – had already suffered years of medical abuse and other harm at the hands of their twisted mom, Sarah Myers, and grandmother, Amy Steadman, Harmon claims in the new, 17-page notice. 

The notice accuses the women of having Munchausen syndrome by proxy – an abusive disorder where caregivers exaggerate, fabricate or induce illnesses in a person under their care – and “regularly drugging” the youngsters by giving them melatonin, Benadryl and Kratom in order “to control them and to make them sick.” 

On one particularly disturbing occasion in May 2024, three of the kids were sent to Albany Medical Center after all four of them became ill and showed signs of having an opiate overdose while attending the Mechanicville City School District – with little Gracelynn even requiring Narcan to revive her, according to the docs. 

The hospital reportedly called Child Protective Services following that incident – which Myers blamed on the kids taking Benadryl – but it should have resulted in the kids being taken from their mother’s care or at least “triggered immediate criminal and abuse investigations,” the court docs charge. 

The notice heart-wrenchingly claims little Gavin got the worst abuse, with the women having him “falsely diagnosed with several mental illnesses and put on a psychotropic medication that reduced his ability to fight back.”

While the kids were chronically absent from school under the guise that Myers was homeschooling them, according to the docs, the agencies “deliberately kept information about the abuse and neglect,” as well as their school and medical records from their father – “in violation of his parental rights and the law.” 

Harmon, who had been embroiled in a bitter custody dispute with Myers, had not seen his children since 2019 – and was eagerly preparing for their upcoming trip to visit him in Utah when investigators found the relatives’ bodies badly decomposed inside their Mechanicville apartment on June 23. 

Over the almost two weeks before that, Harmon claims in the filing that he repeatedly requested welfare checks from police – who only entered the apartment after a neighbor eventually called 911 about a foul smell coming from the unit. 

In a sick letter discovered by authorities after the slayings, Myers alleged that Harmon had abused her and her children, and that the killings were the only way to save them from further abuse. 

Harmon has denied the abuse claims and claimed in the legal notice that his ex-wife used that narrative in order “to gain sympathy, resources (including public resources), and money, and to otherwise control, manipulate, abuse and harm the children.”

At the same time, the agencies – including the Mechanicville Housing Authority, which oversaw the apartment complex where they lived – failed to intervene and allowed the abuse to continue. 

The children stayed inside the home, even despite “multiple complaints and investigations” by CPS, Harmon’s lawyer, Nicholas Liakas, told The Post. 

Among the defendants listed in the notice, “Child Protective Services failed these children,” Liakas said. 

“When the warning signs are there, people need to step up,” the attorney continued. “We can’t wait until a tragedy occurs to say what should have been done before these children are abused.”

Another goal of the legal fight is “to institute change to protect all of New York and all of its children, [who] are the most vulnerable and have nowhere else to turn,” Liakas said. 

“What we’re doing is we’re seeking justice for this family, but we’re also trying to implement institutional change here.”

The Ballston Spa Central School District, who is listed as a defendant in the filing, declined to comment. 

The City of Mechanicville, Saratoga County, the Mechanicville City School District and the Mechanicville Housing Authority did not immediately respond to requests for comment.