Authorities released additional information surrounding the deaths of a Michigan mother and her three daughters whose bodies were reportedly found in a car on Monday.

The Kent County Sheriff’s Department announced Wednesday afternoon that the medical examiner ruled the deaths of Alaina Rau, 2; Cassidy Rodery, 6; and Kyrie Rodery, 8, and homicides and determined their mother, Aubrianne Moore, 28, died of suicide.

Police believe Moore had picked Cassidy and Kyrie up from school around noon Monday and drove the three girls to their grandparents Solon Township home—shooting them with her boyfriend’s legal bolt-action hunting-style rifle in a wooded area behind the residence, according to WOOD-TV.

Moore allegedly placed the girls’ bodies in her car and drove down the street to her boyfriend’s home. Police said it was there she exited her car and fatally shot herself. WOOD-TV reported that the bodies were discovered around 3 p.m.

Sheriff Michelle LaJoye-Young said the mother-of-three didn’t leave a suicide note but previous writings suggested she was worried about a nonexistent threat.

“She believes she was protecting the kids from something and most of her writings really followed kind of in that line,” the officer said.

The murder-suicide comes months after Moore was reportedly hospitalized following concerns regarding her mental health. According to WZZM, Moore was hospitalized in Grand Rapids for more than a week in September after a doctor found she was a danger to herself and couldn’t fulfill her basic needs.

Seeking treatment at a medical facility for at least 90 days, a doctor diagnosed Moore with schizophrenia in the petition and said she was suffering from severe hallucinations and paranoia, according to the petition.

It remains unclear what prompted doctors’ involvement.

“I believe the individual has mental illness and as a result of that mental illness the individual can reasonably be expected within the near future to intentionally or unintentionally seriously physically injure self or others and has engaged in an act or acts or made significant threats that are substantially supportive of this expectation,” a social worker wrote in September’s petition, according to WOOD-TV.

“Aubrianne is keeping her kids home from school because the television told her there would be a school bus accident today. Aubrianne stays awake at night believing people will break into her home. Aubrianne is not eating believing food is being poisoned.”

Despite the petition, the Children’s Ombudsman’s Office told the news that Children’s Protective Services never had contact with Moore or her three kids. Moreover, school district officials said they believe she had sole custody and that there weren’t any court orders restricting her parental rights.

[Featured Image: Alaina Rau, Cassidy Rodery, Kyrie Rodery, Aubrianne Moore/WOOD-TV]