Updated

A Harvard professor says a CNN Headline News host's relentless questioning of a Florida mother three years ago contributed to her suicide.

That's according to a filing in a wrongful death case brought by the family of Melinda Duckett. Duckett's 2-year-old son was reported missing in 2006, and CNN host Nancy Grace launched aggressive nightly coverage of the case.

Click here for photos of police evidence.

The family claims that Grace's questioning and CNN's coverage decisions inflicted severe emotional distress on the young mother. Grace interviewed Duckett after speculation had begun about the mother's alleged involvement in the toddler's disappearance.

The next day, Duckett shot herself in the head.

Dr. Harold J. Bursztajn, a Harvard clinical professor of psychiatry writes that the CNN interview inflicted public humiliation and was "a substantial contributing cause" of Duckett's death. CNN and Grace have denied any involvement in the suicide.

Trenton Duckett has still not been found, and his mother remains the only suspect.