Italy ? An American student who denies murdering her British roommate testified Saturday that she was shocked by the death of a woman she considered her friend, and said a “crescendo” of police pressure led her to accuse an innocent man.

Amanda Knox of Seattle had already told the court on Friday that she was not in the apartment she shared with Meredith Kercher on the night in 2007 when the British woman was slain.

Knox, 21, and Italian co-defendant Raffaele Sollecito, her ex-boyfriend, are accused of murder and sexual violence in the slaying of Kercher, who was found in a pool of blood Nov. 2, 2007, in the shared apartment in the central Italian town of Perugia.

Knox took the stand for the first time Friday and said she spent the night of the killing at Sollecito’s apartment. Prosecutors believe Knox, Sollecito and a third suspect convicted in a separate trial went to Kercher’s home the night of the murder and killed the British woman in what began as a sex game.