Meredith Kercher, 21, died of a stab wound to the neck Nov. 2. A bloody fingerprint found on a pillow at the crime scene implicates a fourth person, "very possibly" a man, an investigator close to the case told CNN.
Amanda Knox, 20, Kercher's roommate from Seattle; Knox's boyfriend, Raffaele Sollecito, 23; and Congolese bar owner Patrick Lumumba, 38, have been arrested in connection with the slaying . All three have denied involvement in the killing.
Knox recanted her initial statement blaming Lumumba for Kercher's
death, saying drugs rendered her confused, CNN reported. Knox so far has given three versions of what occurred that night. DNA belonging to Kercher and Knox was found on a knife belonging to Sollecito in his apartment, police said.