Days after 42-year-old Christy Sheats shot her two daughters at their family home, ultimately resulting in their death, officials say that fateful day wasn’t the first time they visited that address.
The Fort Bend County Sheriff’s Office released a statement Monday detailing the 14 other times deputies paid the family’s Houston, Texas, home a visit since 2012.
While officials say some of the calls were related to alarms issues, sheriff’s office spokeswoman Caitilin Espinosa told PEOPLE police had made previous calls involving Sheats’ “mental crises” and “altercations.”
Officials haven’t gone into great detail about Sheats’ history of mental health issues, but psychologist Dr. Jeff Gardere tells “Inside Edition” that killing your own children, also known as filicide, often means there’s something “much deeper” at play:
“This is something that is absolutely shocking and therefore, this isn’t just about someone losing her temper and then killing her daughters. There is something much, much deeper going on. You have to ask yourself, ‘How could this go so wrong?’”
According to a study published by the US National Library of Medicine, researchers found it difficult to pinpoint the type of woman who would murder her own blood, but definitively said:
“The strongest general risk factor that was identified through an analysis by Friedman was a history of suicidality and depression or psychosis and past use of psychiatric services.”
Medical experts also noted that mothers who were “socially isolated, indigent, full-time care providers who may have been victims of domestic violence themselves” were at highest risk to commit filicide.
A neighbor who knew the Sheats told ABC 13 News Christy and her husband, Jason, had recently reunited after being separated.
Over the last three decades, researchers at Brown University say filicide rates have remained “steady” at around 500 a year.
Dr. Timothy Mariano, lead author of the study, hypothesized three potential reasons for “underlying motives” of people who kill their own children:
“One is that at least some parents who commit filicide have mental illness that derives from low levels of the neurotransmitter serotonin. Not only is that borne out in some animal studies, but the most typical ages of filicidal parents in the SHR data (18-30 years) are also the age at which many serotonin-related illnesses occur, like depression and schizophrenia.
A second hypothesis focuses on sex hormones. High levels of testosterone appear to coincide with higher rates of filicide in animal studies, for example, and in the crime statistics men were more likely to commit filicide, especially after victims were older than a year.
The final hypothetical motive category pertains mostly to those youngest of victims, “the unwanted child.” This evolutionarily motivated idea, also informed by other studies, suggests that parents, particularly young mothers, may kill young children who are sick or for whom they feel they cannot provide care.”
Statistically speaking, mothers are found to be slightly more likely to kill their daughters than fathers, which is exactly what happened to the Sheats family.