(CBS) — There is a push to free a woman convicted in the death of a baby at a Lincolnshire daycare.

Ben Kingan died after collapsing at the daycare in 2009. One daycare worker is now convicted in his death, but a mysterious phone call has brought new attention to the case.

CBS 2’s Dana Kozlov reports Paul Calusinski’s Carpentersville home is filled with ‘Free Melissa’ buttons, posters and now new hope.

“This time not only do I believe that something truly is going to happen, I believe in her attorneys,” he said.

In 2012, his daughter Melissa Calusinski was convicted of killing 16-month-old Ben Kingan at the Lincolnshire daycare where she worked.

Lake County prosecutors say she confessed to throwing the toddler to the ground, fracturing his skull. Her attorney Kathleen Zellner now says the confession was not only coerced, she also implies Calusinski was framed.

In a post-conviction petition filed this week, Zellner writes Calusinski was “convicted based on irrefutably false medical evidence offered by the state’s testifying experts.”

Specifically, Zellner claims the prosecution’s medical expert now admits, “he failed to correctly identify Ben’s chronic subdermal hematoma,” a prior head injury that even Lake County’s current coroner Thomas Rudd is on record saying likely caused Ben’s death.

In an affidavit, Rudd also states Paul Calusinksi got an anonymous call tipping them to another set of x-rays that show Ben never had a skull fracture.

“We need to get to the truth about what happened to this little boy and I think the truth’s now coming out,” Paul Calusinksi said.

Calls to current Lake County State’s Attorney Michael Nerheim and Ben’s parents were not returned.

It’s now up to a judge to decide what, if anything, should happen next.