"The choice you made that morning was not an act of love. It was a crime," a judge told Bonnie Liltz
Credit: Schaumburg Police Department

The terminally ill Illinois mother who gave her daughter a lethal dose of drugs because she feared what would happen to the severely disabled 28-year-old if she died was sentenced to four years in prison on Wednesday, PEOPLE confirms.

Even though prosecutors had recommended probation, Cook County Judge Joel Greenblatt sentenced Bonnie Liltz, 56, to prison, saying, “The choice you made that morning was not an act of love. It was a crime.”

The Schaumberg, Illinois, woman was immediately taken into custody.

Later, the Cook County State’s Attorney’s Office released a statement about the verdict, explaining why they sought probation instead of prison.

“This case was a tragedy for everyone involved and given the very tragic extenuating circumstances, we felt that a term of probation rather than imprisonment was the appropriate sentence,” read the statement.

Liltz, who suffers from recurring cancer, feared she was dying when she gave her daughter, Courtney Liltz, a fatal dose of prescription medication on May 27, 2015, to spare her from being institutionalized, her attorney, Thomas Glasgow, tells PEOPLE. Liltz tried to take her own life, but survived.

She was initially charged with first-degree murder for her daughter’s June 5, 2015, death, which carries a minimum 20-year sentence if convicted. After prosecutors agreed to reduce her charge, she pleaded guilty on May 10 to involuntary manslaughter.

Prosecutors recommended four years of probation and therapy instead of prison.

In an emotional plea to the court on May 11, Liltz said she wished she could “turn back the clock” and care for her daughter again, adding that adopting Courtney was the “happiest day of my life,” the Chicago Tribune reported.

Longtime Health Challenges

Liltz was diagnosed with Stage III ovarian cancer when she was 19, Glasgow says. Harsh radiation treatments destroyed her intestines and a hysterectomy left her unable to have children of her own, he says.

“She can’t take in nutrition or water and weighs less than 100 pounds,” he says.

In 1992, after meeting Courtney while volunteering at churches, agencies and homes, she adopted the girl, who suffered from several severe disabilities, including cerebral palsy, and required near-constant care.

Liltz, a single mom, embraced the child and took excellent care of her, says Glasgow.

“Every person we interviewed indicated that Bonnie took immaculate care of this child. The doctor said she was in perfect condition. She was well fed and always clean.

“Bonnie made sure they socialized with people and would take her out for walks,” he says. “She kept the house clean and pristine. She slept on a twin bed next to Courtney every night.”

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When Liltz underwent a major surgery in 2012, she was forced to leave Courtney in a state-run institution, since she had no one to care for her during the week she was hospitalized, says Glasgow.

“Her parents are in their late eighties and cannot care for Courtney,” he says. Liltz’s sister cares for their wheelchair-bound mother, who suffers from rheumatoid arthritis.

“In Illinois, parents can get help for their disabled children until they are 22,” says Glasgow. “After that, there is no assistance, and if necessary, they have to go into state-run institutions. When Bonnie went in for her surgery, Courtney had to go to one of those institutions.”

After Liltz’s surgery, she returned to the home where Courtney was staying and was shocked at what she found, he says.

“Courtney was sitting in her own filth,” he says. “She was wearing clothes that were wet from her drool. Courtney wouldn t even look at her mother. She was angry and upset and wondering why she had been left alone.”

Recurring Health Problems

In 2015, when Liltz’s health began to deteriorate even further, she worried about what would happen to Courtney if she were hospitalized again – or died.

“Her doctor said, ‘Your intestines could fail at any time and if they do, you could die,'” says Glasgow.

On the morning of May 27, 2015, Liltz thought her intestines were, in fact, failing when she woke up covered in feces because her diarrhea wouldn t stop, says Glasgow.

“She said she knew she was going to die and ended up making a fateful decision,” he says.

Using medications that she and Courtney had been prescribed, including opiate-based drugs, Liltz opened up capsules and put them in Courtney’s feeding tube.

“Bonnie also ingested a large amount, thinking it was going to kill her as well.”

After Liltz’s sister found her and Courtney unconscious on their beds, they were taken to the hospital. Liltz was able to recover, but Courtney died several days later.

“It broke Bonnie’s heart,” he says. “She said to me in the hospital, ‘I want to be with my daughter,’ and to this day she still says she wants to be with her and cant wait to see her again.”

“This is the saddest case I have ever worked on,” he says.