Kailey Erhart, 22, faces charges of two counts of murder and one count of attempted murder following an incident on August 6 in Mandan, North Dakota. Police allege Erhart killed her infant daughter Ava and her three-year-old daughter Morgan, while their one-year-old brother Colton survived serious injuries.
According to a police affidavit, the confrontation began when Erhart allegedly held a pistol and told her husband, Cameron, "Say goodbye to your kids." Cameron managed to disarm her, but the situation escalated, and Erhart allegedly pursued Cameron and his mother with a kitchen knife as they attempted to secure the children. The affidavit details how Erhart allegedly retrieved the infant Ava from a car before securing all three children inside the home.
When law enforcement arrived, they found Erhart with the knife to her own throat. Inside, they discovered Colton and Ava with neck injuries. Ava died at the hospital that evening, and Morgan died the following morning. Colton, who also sustained neck injuries, miraculously survived and has since been released from the hospital.
In the aftermath, Erhart reportedly told police she recalled chasing her husband and his mother with the knife and the events following the attack but had no memory of harming her children. Her father-in-law, Bryce Erhart, expressed suspicion about this alleged memory lapse, telling the Daily Mail that he believes the killings were premeditated and motivated by revenge. He also claimed that Erhart had repeatedly threatened to harm the children if Cameron pursued a divorce.
The family fears that Erhart may attempt to use a mental health defense, potentially postpartum psychosis, citing similarities to the recent mistrial of Lindsay Clancy in Massachusetts, who was accused of killing her three young children in January 2023. Clancy also claimed postpartum psychosis. Bryce Erhart, however, distinguishes his daughter-in-law's case, asserting that her actions were not due to extreme psychosis but were premeditated acts intended to harm Cameron.
Bryce Erhart also raised concerns about the Child Protective Services' (CPS) handling of the situation, stating that Cameron had attempted to contact CPS due to concerns for the children's safety, but felt the agency's follow-through was insufficient. He noted that even after psychiatric treatment in 2025, restrictions placed on Erhart were short-lived. Following the tragedy, Bryce claimed CPS temporarily removed Colton from Cameron's care, which he found particularly distressing given the circumstances.
Forensic psychologist Dr. Jennifer Prohaska, who has not evaluated Erhart, commented that postpartum depression, intrusive thoughts, and postpartum psychosis are distinct conditions, with psychosis involving a distortion of reality. She cautioned against retrospectively interpreting past mental health struggles as proof of psychosis. Erhart is scheduled to enter a plea on October 6.
The family's immediate focus is on supporting Colton, who is physically recovering and undergoing therapy. Bryce Erhart shared that the surviving child continues to ask for his baby sister. "Ava was his favorite little baby," he said. "He says Ava all the time. He's like, 'Ava, Ava, Ava,' because he'd always go up and hold her and kiss on her."