"And I wouldn't suggest it," Ernie replied, smiling slightly at her Pansy comment. "That girl can be vicious. I wouldn't trust any of the Slytherins in our year really, although I haven't spoken to several of them, so perhaps that is a bit unfair."
Ernie nodded. "Yes, those two. They are the prime suspects, and I think the Slytherins know it too. And I think... well, itching powder isn't in the WWW catalogue, so perhaps it was in testing and they weren't aware of it's potential?" Ernie didn't think they would try to hurt anyone unless someone was trying to hurt them. They weren't malicious people, and he knew that. Fiercely independent, trouble-making, all sorts of things, but not malicious.
Shaking his head, Ernie replied, "No! They're good at what they do, and I can't find any proper proof. Daphne destroyed her package, which is perfectly logical, but not particularly helpful now. She couldn't even describe the owl. Astoria never replied. There's no proof, so we can't act on anything." Ernie felt absolutely stumped, and frustrated.