Carolina Picchio killed herself in January after she got a barrage of vulgar messages reportedly prompted by a video posted on Facebook of her drunk at a party.
Carolina's sister, Talita, told CNN that she and some of Carolina's friends reported the abusive messages and comments to Facebook, but nothing ever happened.
"In the case of Carolina, it appears some of her friends, some of her relatives, asked for the removal of some of this strong content, and it wasn't removed — and this played a role in her decision to commit suicide," prosecutor Francesco Saluzzo told CNN.
Before jumping to her death, Carolina updated her Facebook status. "Forgive me if I'm not strong. I cannot take it any longer," she wrote, The Daily Beast reported.
Facebook responded to CNN's inquires, saying, "We are deeply saddened by the tragic death of Carolina Picchio and our hearts go out to her family and friends."
"We remove content reported to us that violates our Statement of Rights and Responsibilities and we escalate reports of harassment and
The Italian Parent's Association has already filed a criminal complaint in Rome accusing Facebook of having a role in the girl's suicide, according to The Telegraph.
Italy has a history of prosecuting Internet crimes. In 2010, the country gave suspended jail terms to three Google employees who failed to remove a video of a handicapped boy getting bullied, according to The Daily Beast.