48 Hours: A troubling conviction?

Reporter Ruth Fuller covered the case of Melissa Calusinski, a former Illinois day care provider who has maintained her innocence in a toddler's death. Fuller also appears on Saturday's "48 Hours" investigation into the case. For Crimesider, she weighs in on evidence that may point to Calusinki's innocence. Her opinions do not necessarily reflect those of CBS News.

I covered the murder case of Melissa Calusinski with the eyes of a journalist and the heart of a mom.

My youngest daughter was not much older than 16-month-old Benjamin Kingan, the victim in this case, and like Benjamin she was also in daycare. I could not bear the thought of something like this happening to her, and my heart broke for Benjamin's family.

I was friendly with the three prosecutors assigned to the case. Benjamin's parents were highly educated and seemed to be good people. By contrast, I had never met the defense attorneys, who were from another county. Melissa had only graduated high school with an extremely low GPA and an even lower I.Q.

It was clear to me, early-on, that I would naturally relate more to the prosecution's side in this case and to Ben's family. But I was determined to be fair in my coverage, as I always am.

As the case progressed, however, my reporting on the trial angered the prosecutors I was once so friendly with because I approached their arguments with the same critical eye I used with the defense. One day I was cornered in a courtroom by one of the prosecutors, who yelled at me and said I was completely biased towards Melissa and didn't care about the dead boy.

During the trial, I was crushed as I watched Ben's parents testify about how his death affected them. It was nearly unbearable to see the autopsy photos, juxtaposed with the pictures of a smiling Ben when he was alive.

I also watched as heartbroken friends, family and co-workers of Melissa took the stand to testify to her character and to her actions the day Ben died.

I was somewhat surprised when the jury found Melissa guilty because I truly thought there was reasonable doubt in this case. But having done this job as long as I have, I knew that juries tend to convict in a child's death, so there is no chance at letting a potential child killer go.

More than a year and a half after her conviction, I got a tip that could change everything for Melissa. The forensic pathologist who performed the autopsy on Ben and insisted the fatal blow to Ben's head occurred on the day he died, had changed his mind. Now he said he'd "missed" a pre-existing head injury.

A disagreement about coverage of this new story caused me to leave my freelance job at the newspaper I worked at for 14 years. I took this new story to a competing Chicago newspaper, where it appeared as a front-page Sunday story.

While the story of Benjamin Kingan and Melissa Calusinski cost me a job and people I counted as friends, I don't regret anything I have done. The tragedies here are that we cannot be sure how Ben died and a woman may be in prison for a crime she did not commit.

This is why I will continue to cover this story, no matter what the cost.