A Harvard professor says CNN Headline News host Nancy Grace's relentless questioning of a Florida mother three years ago contributed to her suicide, according to a filing in the family's wrongful death case.

Grace launched aggressive nightly coverage of 2-year-old Trenton Duckett's case shortly after he disappeared in 2006, usually with a collection of analysts. When the boy's mother, Melinda Duckett, appeared by telephone two weeks into the case, speculation was beginning to narrow on her possible involvement.

Dr. Harold J. Bursztajn, a clinical professor of psychiatry, wrote in a filing this week. that Grace "struck a highly accusatory tone."

The professor saw "a distraught young woman who is subject to repeated and increasingly sharp questioning by a hostile interviewer who displays increasing suspicion and anger towards Ms. Duckett."

The next day, the 21-year-old Duckett shot herself in the head.

"Her apparently unanticipated public humiliation on the nationally televised program in question was a substantial contributing cause of her suicide," Bursztajn wrote.

The family claims Grace's questioning, along with the network's decision to air the pre-taped interview the day Duckett committed suicide, inflicted severe emotional distress.

Grace and the network have denied any involvement in the suicide, and a CNN spokeswoman declined comment on the filing.

Trenton has still not been found, and Duckett is the only suspect.

___

Information from: Orlando Sentinel, http://www.orlandosentinel.com