Life terms urged for killers of student

They want the fixed-length terms given to American student Amanda Knox and her former Italian boyfriend for the 2007 murder of the exchange student to be increased to life terms.

The 21-year-old, from Coulsdon in Surrey, was stabbed to death in the flat in Perugia that she shared with Knox in November 2007.

Prosecutors during their trial argued that Knox stabbed her room-mate in the throat during a sex game involving the American student's boyfriend Raffaele Sollecito and another man, Rudy Hermann Guede.

Sollecito and Knox were found guilty of murder in December following a lengthy trial, during which they were kept in custody.

Knox, 22, from Seattle, was sentenced to 26 years in prison, while Sollecito, 25, received 25 years, and both are serving their sentences in Italian prisons.

An appeals court last year shaved 14 years off Guede's sentence because he was the only one of the defendants to apologise to Miss Kercher's family.

The 21-year-old, who was arrested in Germany after going on the run after the murder, denied killing Ms Kercher, 21, a Leeds University student, but acknowledged he should have done more to help her as she lay bleeding in her room.

The appeals court in December upheld Guede's conviction from an earlier fast-track trial for sexual assault and murder but cut his prison sentence to 16 years from 30.

Both Knox and Sollecito are appealing against their convictions.