This article originally appeared on People.com.

The crictally ill Illinois mother convicted in 2016 of killing her severely disabled daughter because she feared what would occur to the 28-year-old after her death committed suicide on Saturday, PEOPLE confirms.

Bonnie Liltz, 57, of Schaumberg, was discovered dead in her own home Saturday evening after members of the family called 911,?Sgt. Christy Lindhurst of the Schaumberg Police Department tells PEOPLE. Her death is “believed to become a suicide,” says Lindhurst, adding that there’s no proof of foul play.

Authorities are awaiting an autopsy and toxicology test results, she says.

In 2016, Liltz was convicted of involuntary manslaughter for that 2015 death of her daughter, who suffered from cerebral palsy. She was sentenced to 4 years in prison.

Liltz, who suffered from terminal cancer along with other health problems,?told authorities that because her health was deteriorating rapidly, she feared she’d soon die. In 2015, she gave herself and her daughter Courtney a lethal dose of drugs because she was afraid no one could care for her daughter. Courtney died from the overdose but Liltz survived.

Even though prosecutors had recommended probation, in 2016, Cook County Judge Joel Greenblatt sentenced her to prison, saying, “The choice you’ve made that morning was not an act of love. It was a criminal offense.”

Later in 2016, a judge set her free on bond during her appeal after she had served around three months from the sentence, WGN9 reported.

In October, the Illinois Top court denied her appeal.?She was scheduled to return to prison on Monday to complete her four-year sentence.

Liltz took her own life because she believed she would die in prison without the proper medical care she needed, her attorney, Glasgow, tells PEOPLE. “She did leave an email to me and to another attorneys who had caused her saying she knew she was going to die if she returned to prison and couldn’t bear to die there,” he says.

Plagued by incontinence issues due to a perforated bladder and bowel from previous radiation treatments for ovarian cancer that destroyed her intestines, Liltz’s health deteriorated rapidly imprisonment, says Glasgow.

On Saturday, Liltz informed her mother she would a film and lunch having a friend. Instead, she wrote out suicide notes to friends and family and swallowed an overdose of pills, WLS-TV reports.