Final answer:
The defense pointed out that there was no forensic evidence, such as DNA or fingerprints of Knox, found on the crime scene which contradicts the prosecution's claim that she was involved and wiped away all traces.
Step-by-step explanation:
The defense in the case you're talking about pointed out that there was an absence of forensic evidence linking the accused, Knox, to the crime scene.
Specifically, the defense highlighted that there were neither physical traces nor biological samples such as shoe prints, clothing fibers, hairs, fingerprints, skin cells, or DNA of Knox found on Kercher's body, her clothes, handbag, or in her bedroom. This suggests that if Knox were actually involved, it would be highly unusual for there to be no forensic traces of her at the scene, bringing into question the credibility of the prosecution's argument that all evidence had been meticulously wiped away.