Amanda Knox Defense Encouraged By Witness Antonio Curatolo's Drug Conviction

01/15/2011 11:43 am ET | Updated May 25, 2011

ROME — A defense lawyer for Amanda Knox, the U.S. college student serving a 26-year prison sentence for the murder of her British roommate, expressed optimism Saturday that a drug charge conviction of a prosecution witness might help the American in her appeal in Italy.

The defense always maintained that Antonio Curatolo, a homeless man in the university town of Perugia, wasn't a credible witness, Luciano Ghirga told The Associated Press in Rome.

Perugia court offices were closed Saturday, and officials could not be reached to confirm Italian news reports that Curatolo had been convicted earlier in the week for dealing drugs. It wasn't immediately known what his sentence was or if he had been jailed.

In the first trial against Knox, Curatolo testified that he saw Knox and fellow murder trial defendant Raffaele Sollecito chatting near the apartment house the night Meredith Kercher was slain in 2007. Sollecito, an Italian who was Knox's boyfriend at the time, was also convicted of the slaying and sentenced to 25 years in prison.

Both defendants are appealing their convictions. The next hearing in the appeals trial in Perugia is scheduled for Jan. 22.

"We have always said that he was not a credible witness," Ghirga said, referring to Curatolo. "It was the court that held he was credible." The drug charge conviction "will be an additional thing to help prove the witness is not credible," Ghirga said in a phone interview.

Seeking new witnesses is a key defense strategy in the appeals trial, with Knox's lawyers hoping new witnesses will refute Curatolo's assertion.

Curatolo had told the lower court that he had seen Knox and Sollecito chatting on a basketball court hear the house where the American woman and Kercher shared a rented flat the night Kercher was stabbed to death. The victim's body was found in a pool of blood in her bedroom on Nov. 2, 2007. Forensic experts said Kercher, her throat slit, died the night before.

Knox and Sollecito were convicted in December 2009 of sexually assaulting and murdering Kercher. Both deny any wrongdoing.

The American's defense has argued that she spent the night of Kercher's slaying at Sollecito's house in Perugia, watching a movie, smoking pot and having sex.

Convicted separately in a lower court trial and an appeals trial of the murder is Rudy Hermann Guede, a young man from the Ivory Coast who acknowledged being in the house the night of the slaying, but denied killing the woman. He is serving a 16-year prison sentence.