Motive in student's slaying eluding police

PERUGIA, Italy, Dec. 19 (UPI) -- Police investigators in the Italian city of Perugia have been unable to determine a motive in the slaying of a British exchange student last month.

While police have arrested three people in relation to the homicide based on solid evidence, they have been unable to learn what prompted the death of 22-year-old Meredith Kercher, the Italian news agency ANSA reported Wednesday.

Police have Kercher's roommate, 20-year-old U.S. citizen Amanda Marie Knox, in custody, as well as Knox's boyfriend, Raffaele Sollecito, and Ivory Coast national Rudy Hermann Guede.

Kercher was found in her Perugia home Nov. 2 with her throat slashed and police allegedly found her DNA on a large butcher knife in Sollecito's kitchen.

Police have alleged that after Kercher was killed, Sollecito and Knox attempted to clean up the scene of the crime using bleach.

ANSA said Guede denied having any involvement in Kercher's death, but admitted to being at the scene of the crime and having seen the killer.