The horrifying murder-suicide that claimed the lives of four children in upstate New York is becoming even more disturbing as toxicology findings shed new light on what happened inside the Mechanicsville home.

According to sources who spoke with NewsChannel 13, all four children had both diphenhydramine, the drowsiness-inducing ingredient in medications such as Benadryl, and kratom in their systems.

Harper Harmon, 13, and his younger siblings, Hudson, 11, Gracelynn, 10, and Gavin, 10, were the victims of the June killings.

Authorities said Harper, Hudson and Gracelynn died after being poisoned. Gavin was killed with a knife while reportedly trying to defend himself.

The new toxicology findings add another deeply disturbing layer to an already devastating case. The children were apparently given substances before the violence unfolded, according to the report.

The killings occurred as the children were expected to spend the summer with their father, Brady Harmon, who lived in Utah. Harmon had been separated from the children's mother, Sarah Myers, and had not seen his children in person since November 2019.

The family was also caught in a bitter custody dispute.

After the killings, authorities discovered a letter in which Myers accused Harmon of abusing her and the children. She claimed the murders were carried out as a way of protecting them from further abuse.

Harmon has denied those allegations.

Following the deaths of his children, Harmon condemned his former wife, saying she deserved “a special place in hell.”

Whatever claims were made during the custody battle, four children are now dead—and the toxicology findings raise even more questions about the final hours of their lives.

This was not simply a family dispute that ended tragically. It was a catastrophic failure of adults to protect four innocent children who should have had their entire lives ahead of them.

As investigators continue piecing together exactly what happened, the focus must remain where it belongs: on the children, the circumstances that led to their deaths, and whether warning signs were missed before the tragedy became irreversible.