Resentful grandma poisoned her 4 grandkids with help from their mom, killed them all so they wouldn't have to spend the summer with their dad

Left: Amy Steadman (Facebook). Right: Sarah Myers and her children (GoFundMe/Facebook).

A New York grandmother who killed her four grandkids — poisoning three of them and stabbing another — was secretly working with their mother to pull off the slayings and researched ways to carry them out, according to newly released police information.

Amy Steadman, 64, took her own life and her daughter, Sarah Myers, 44, did the same after the two executed their murder-suicide plan, according to Mechanicville Police Chief Bill Rabbit, who held a press conference Tuesday to release new details uncovered during the department's investigation.

Electronic communications recovered during the investigation show that Steadman and Myers discussed "obtaining medications, where the murders would occur, how those medications would be administered, how the children would be brought together, what they would be told, and how suspicion could be avoided" in the days leading up to the slayings, according to Rabbit.

"Those communications are important because they document far more than planning," Rabbit told reporters. "They show that Steadman and Myers were communicating and coordinating while the murders were taking place."

Steadman's grandchildren Harper Harmon, 13, Hudson Harmon, 11, and twins Gavin Harmon and Gracelynn Harmon, both 10, were all found dead on June 23 in Steadman's Mechanicville apartment. Handwritten letters and other items inside Steadman's home "strongly" suggested that the 64-year-old was planning the murders with Myers as a way to stop the children's father, who lives in Utah, from allegedly abusing them.

There is also evidence that Steadman visited several pharmacies before the killings.

"She obtained multiple doses of over-the-counter sleep aids and picked up medication that had been prescribed to her," Rabbit explained Tuesday. "Investigators also recovered internet search history from Amy Steadman's home showing searches involving medication reactions, the effects of insulin on non-diabetics, and the Utah court system."

In one alleged search, Steadman wrote, "Where's the most fatal place to be stabbed?"

She wrote "find the carotid artery in the neck" in another.

According to police, Steadman resented her grandchildren's father after he was granted custody of them. Local CBS affiliate WRGB obtained court documents showing Myers and the father divorced in 2020 and were initially both granted joint custody.

In the letters Steadman and Myers left behind, both claim their murder-suicide plan was the only way to stop the children's dad, Brady Harmon, from allegedly harming and abusing them.

During the police investigation, cops recovered electronic files belonging to Myers that included images "appearing to document" injuries to Myers and some of the children, including text messages and handwritten materials alleging abuse.

According to WRGB, the custody agreement between Myers and Harmon allowed Myers to have the children during the school year, while Harmon got uninterrupted time with them during the summer months from July to September.

"[Steadman] accepts responsibility for what occurred and states that they believed killing the children was the only way to keep them safe from alleged abuse in Utah," Rabbit said.

"[Myers] repeatedly referred to 'My babies,' expressed anger towards the Utah family court system, [and] made allegations that she and her children had been abused while living in Utah," Rabbit said.

When it came time to poison the children, the kids all "failed to respond in the manner Steadman and Myers had anticipated" to the medication being given to them, according to Rabbit.

A text message between Steadman and Myers says, "It's not working. We need another option."

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Investigators also recovered a message sent by Gracelynn. "Why would you do that? You both won't let me puke," as she described experiencing "increasing pain" in her stomach, according to Rabbit.

The child who was stabbed, Gavin, had a defensive wound "indicating that he attempted to protect himself," according to Rabbit.

The family had all been dead "for an extended period of time" before police found them while performing a welfare check. A concerned neighbor didn't see them for several days and notified authorities. The bodies were too badly decomposed for responding officers to immediately identify them, according to Rabbit.

"I went from, 'I'm seeing my kids,' to 'I'll never see my kids again,'" Harmon told the Times Union, a local news website in New York.

Harmon said his ex-wife had kept the kids from him, only allowing for an occasional FaceTime. He told the Times Union he wanted to bury the children in Utah to keep the kids "as far away as possible from their mother."