Desirée Mariottini, a resident of Cisterna di Latina, was found dead early on October 19 at an abandoned building in the Roman district of San Lorenzo.
Though the cause of the girl’s death is not yet clear, an autopsy revealed that she had drugs in her system and had been sexually assaulted more than once.
Police are currently treating the death as a suspected homicide.
On October 17, Mariottini had telephoned her grandmother to say she’d missed the last bus home and was going to stay at a friend’s house in Rome, the family’s lawyer, Valerio Masci, said on Wednesday.
The next day she was reported missing, and on October 19, her body was found following an anonymous phone call to emergency services at 3:00 am.
The building in which Mariottini’s body was found is reportedly home to squatters, and firefighters had to force open a padlocked door to allow paramedics to enter.
Authorities said the case was initially misreported by police, who described the victim as a woman aged between 25 and 30, who died of an overdose.
They failed to report any apparent signs of violence.
A witness has since come forward, claiming he’d been at the building at around midnight and that when he arrived, “there was a woman screaming”.
He said the woman was Italian, and spoke in Roman dialect.
“There was another girl on the bed; they had put a blanket over her but you could see her head,” the man said on Rai television show Storie Italiane.
“I don’t know if she was breathing, she seemed dead already. The other girl was screaming and saying she was dead.”
The witness claimed there were six or seven other people in the room at the time.
Flowers and candles have been laid in San Lorenzo in a tribute to Mariottini, and a wall has been painted with red hearts and the words: “Giustizia per Desiree. San Lorenzo non ti dimentica” (Justice for Desirée. San Lorenzo does not forget you).