Prosecutors said Thursday that they have wrapped up their investigation into the slaying of a British student, paving the way for possible indictments of her American housemate and two other suspects.

Amanda Knox, 20, of Seattle; her former Italian boyfriend, Raffaele Sollecito; and Rudy Hermann Guede, a citizen of Ivory Coast, have been jailed since Nov. 6 in connection with the death of Meredith Kercher, Knox's housemate.

Kercher, a 21-year-old student from Leeds University in England, was found dead in a pool of blood in the house in the Umbrian university town of Perugia that she shared with Knox. Prosecutors say she was killed resisting sexual assault, and were investigating the suspects on suspicion of murder and sexual violence.

All three suspects have denied any wrongdoing.

The defense now has 20 days to request further questioning or produce more documents before prosecutors either seek indictments or drop the accusations.

In the court document that officially notified the defense that the investigation was over, prosecutors contend that the three suspects strangled and stabbed Kercher. They also contend in the document that Guede committed sexual violence on Kercher, with the help of Knox and Sollecito. Prosecutors also contend that Knox and Sollecito tried to make it appear that an attempted robbery had taken place in the house, the document said.

Both Knox, a student at the University of Washington, and Sollecito have given conflicting statements, saying they had smoked hashish the night of the slaying, according to other court documents.

Sollecito has maintained that he was at his own apartment in Perugia, working at his computer. He has said he does not remember if Knox spent the whole night with him.

Knox has insisted she was not at home during the slaying, although at one point in the investigation, she accused a Congolese pub owner, Diya "Patrick" Lumumba, of killing Kercher. Lumumba was arrested in but quickly released for lack of evidence. He was formally cleared last month.

Knox's DNA has been found on the handle of a knife that prosecutors say might have been used in the slaying, while Kercher's DNA was found on the blade.

DNA testing has found that Guede, whose fingerprint was found in bloodstains on Kercher's pillow, had sex with Kercher the night she died. Guede, 21, has acknowledged being in the woman's room that night, but said he did not kill her — and that an Italian who is trying to frame him did. It is not clear who Guede accused.

Guede was arrested in Germany and extradited to Italy. He is believed to have fled shortly after the slaying.