Nearly a year after a judge overturned the murder conviction of a former suburban day care worker accused of killing a newborn in her care, the woman is suing investigators for allegedly withholding evidence and fabricating scientific findings, according to court documents. Jennifer Del Prete, 46, spent nearly a decade in prison after she was found guilty of first-degree murder in the 2003 death of 14-month-old Isabella Zielinski. Authorities accused Del Prete of shaking the 4-month-old at the day care where Del Prete served as a caretaker. The baby died about 10 months later. During her trial, a state medical expert testified that Isabella's injuries could have been inflicted only on the day she became unresponsive, ignoring evidence that the baby had suffered an unexplained brain injury days earlier. A Freedom of Information request filed by journalism students at Northwestern University's Medill Justice Project uncovered a memo written by the lead Romeoville detective who worried that the pathologist who conducted the autopsy did not agree with the shaken baby syndrome theory.