Testimony in Amanda Knox's murder trial today challenged prosecution arguments that bloody footprints at the crime scene belonged to Knox's co-defendant and ex-boyfriend Raffaele Sollecito.
Knox and Sollecito claim they are innocent of the crime and that they were together in Sollecito's apartment on the night that Knox's English roommate, Meredith Kercher, was killed. The prosecution's argument that the bloody footprints belongs to Sollecito threatens their defense by placing him at the murder scene.
Knox, 22, a Seattle student who was studying in Perugia, is accused, along with Sollecito, 25, of murdering Kercher, with whom she shared a cottage in this picturesque Italian hilltown. Kercher, 21, was found semi-naked with her throat slashed on Nov. 2, 2007.
A third person, Rudy Guede, 22, was convicted in October 2008 and sentenced to 30 years in prison for his role in the murder. He admits to being at the scene of the crime, but says he did not kill Kercher, and has appealed his conviction.
Francesco Vinci, a coroner and forensic specialist for Sollecito, told the court in Perugia, Italy, that the foot prints in the blood did not come from Sollecito.
Vinci's testimony focused on two out of four bare footprints found on the scene of the murder: a bloody footprint found on the rug in the bathroom, and a luminol-enhanced print found in the hallway of the cottage where the girls lived.
During testimony in May, both of these prints were attributed to Sollecito by the prosecution.
Vinci said he analysed the features of Sollecito's feet. "You look for peculiarities in the print to distinguish one print from another," he told the court. Vinci noted that among the distinguishing features of Sollecito's right foot is that the second toe is a hammer toe, so it does not leave an imprint.
Using a series of slides featuring photographs, grids and measurements, Vinci compared the partial print on the rug with an ink-print of Sollecito's right foot that was taken in prison.
His presentation featured Crimescope images that changed the color of the original photographs into yellows and browns, which, Vinci said, highlighted the details of the prints. Police investigators had not used the Crimescope in their investigation, the forensic expert pointed out.
Vinci told the court that he was given access to the bathroom rug at forensic police headquarters in Rome, and he studied it in person and based his measurements of the print on his own photographs.
Vinci concluded the bloody footprint should be attributed to Guede because of the shape and angle of the big toe and the width of the ball of the foot.
"I am not saying that this print certainly belongs to Guede," said Vinci, "but it is attributable to Guede, it is compatible."
The prosecution found just the opposite in May. Police print expert Lorenzo Rinaldi found that Sollecito's big toe was much wider than that of either Knox or Guede, as was the ball of his foot and the arch. Rinaldi said at the time that "it can absolutely be concluded that the print is compatible with that of Sollecito and not compatible with that of Guede. It gives us a probable identity of Raffaele Sollecito."
As part of his presentation, Vinci did an overlay of Guede's print on the print found on the rug, showing how it matched, but he did not do the same with Sollecito's print, as the prosecutor later pointed out. Vinci said he did not feel it necessary to make that comparison.
Vinci has also argued, however, that an absolute positive identification cannot be made based on the foot prints on the rug because, unlike a finger or toe print made on a hard surface, it does not show the distinguishing ridges that make up an individual's specific print. One can only speak of "compatibility" and "probability," and not of a definitive identification, he said.
In regards to the luminol-enhanced print in the hallway, Vinci said his measurement showed it to be considerably shorter than Sollecito's foot. He did not say whether he thought it could belong to Knox. Rinaldi in his report in May attributed two other luminol-enhanced prints to Knox, but said this one was Sollecito's.
Vinci also testified about two vague traces of bloody shoe-prints that were found on a pillow under the victim's body. While the police believe that one is a partial print of the bottom of Guede's right sneaker – a Nike Outbreak2 - and the other the heel of a smaller shoe, probably a woman's, Vinci testified today that his analysis showed both prints were from a left shoe, a Nike Outbreak2.
In addition to foot and shoeprints, Vinci presented his interpretation of some blood stains found on the mattress cover of Kercher's bed. He said that he believes those stains were made by a bloody knife – two prints by the same knife – that is a much smaller knife than the one police claim is the murder weapon.
The trial continues on Saturday with testimony from three court experts about the time of death of the victim, evidence of sexual assault and discussion of the possible murder weapon, a kitchen knife. The knife is expected to be shown in court for the first time.