Amanda Knox, Her Next Move: Appeal of Murder Conviction Escalates to Higher Gear

Amanda Knox (AP/Alessandra Tarantino)

NEW YORK (CBS) Amanda Knox's appeal of her murder conviction in Italy has moved into a higher gear. Knox's lawyers Saturday filed a 201-page document appealing her Dec. 2009 conviction for the murder of her former college roommate, Meredtih Kercher.

The filing challenges the Seattle native's guilty verdict on three key points: her long, initial interrogation by police when Knox says she was forced to confess, what her lawyers call the prosecutor's contradictory evidence, as well as what they claim is shaky DNA evidence used to convict her. 

The 26-year-old Knox is serving a 26-year sentence in an Italian prison.

Just days before Knox's appeal, prosecutors in the case dealt her case a potential blow by filing their intent to  try to increase Knox's punishment to life in prison, according to the Italian news agency ANSA.

In the formal notice to extend her sentence, prosecutor Giuliano Mignini cited Knox's "lack of remorse."

Edda Mellas, Knox's mother, says that's "ridiculous."

"Amanda showed a lot of devastation over the loss of her friend," Mellas told CBS News' "The Early Show." "But... you don't apologize for something you didn't do."

Knox's Italian ex-boyfriend Raffaele Sollecito was also sentenced in Kercher's 2007 killing. He got 25 years. Rudy Hermann Guede, an Ivory Coast national, was convicted of murder in a separate trial. He received a 30-year sentence, which was reduced to 16 years on appeal.

A 48 Hours | Mystery investigation questioned the evidence, including the alleged murder weapon, the condition of DNA evidence, and the bizarre theory of the crime, which may have come from a television psychic rather than police work.

48 Hours | Mystery looked at the case in a recent episode.

PICTURES: Verdict In Italy

April 15, 2010 - Amanda Knox Framed: Picture Hung in Italian Police "Hall of Shame" BEFORE She Was Charged With Murder
March 18, 2010 - Amanda Knox Italian Police Bombshell: We Knew She Was Guilty of Murder Without Physical Evidence
March 4, 2010 - Italian Judges Still Sure Amanda Knox a Killer

December 23, 2009 - Rudy Hermann Guede Will Get Out of Jail Before Amanda Knox for Meredith Kercher's Murder
December 16, 2009 - Amanda Knox May be Joined in Jail by the Prosecutor That Put Her There
December 4, 2009 - Amanda Knox Verdict: Italian Jury Will Announce Decision at 6 P.M. Eastern
December 3, 2009 - Amanda Knox Pleads With Jury: I'm No "Assassin"
December 1, 2009 - Lawsuits Fly in Amanda Knox Murder Trial
November 24, 2009 - Amanda Knox: Sex-Game Murder Charge is "Pure Fantasy;" Italian Prosecutors Want Life Sentence
November 20, 2009 - Amanda Knox Trial: Convicted Killer Fingers Knox for Meredith Kercher Murder
June 19, 2009 - Knox's Mom Says Daughter, Victim Got Along
June 15, 2009 - "Always A Crescendo:" Amanda Knox Talks About Murder Investigation On Stand
June 12, 2009 - Knox's Alibi: Sex, Drugs And Sleep