When cats take swipes, they do it with claws extended. We found a spot of blood on Q-tip but when we cleaned the wound we found lots more scratches all over her butt and back. She looked like Wolverine had tried to shave her, quite ineptly too.
Back at the crime scene, we examined each cat's claws for blood trace, but the perfect crime had been committed. No blood to be found anywhere to indicate which suspect was the perp. Regardless, each of them will get their claws trimmed today, just to be safe.