According to reports, two Senegalese nationals aged 26 and 43 were reportedly held overnight. A third suspect, a 40-year-old Nigerian, was detained yesterday.
The three are expected to be charged with group sexual violence, voluntary manslaughter and drug dealing. All three are reported to have previous convictions for drug dealing.
Police in Rome are still hunting at least one other suspect, local media reports.
The 16-year-old girl was found dead in a derelict building used as a squat in San Lorenzo.
Investigators believe Desiree was drugged and then gang raped while unconscious before she died.
Though the exact circumstances and cause of the teenager’s death are yet to be confirmed, an autopsy revealed that she had been under the influence of drugs and had been sexually assaulted.
An anonymous call was made to emergency services at 3am on the 19th of October, local media reported.
Flowers and candles have been laid outside the building in a tribute to Mariottini, and local residents have painted the walls with red hearts and the words ‘Justice for Desirée. San Lorenzo does not forget you’..