Translation:I do not know whether she used a knife or a bottle.
The outside security camera recorded she leaving the house with a knife in her boots. That's clear. But I believe this was her intention. Some small pieces of broken glass were also found in the kitchen. There was a fight. She committed the murder with a bottle, cleaned the mess, took a clean a knife and put it in her boot, then ran away. She reasoned that if she were caught, the DNA analysis of the knife would return null results. Exactly where we are now...
As you mention it, I really miss the details about the wounds. If I want to read a good Italian detective story, I must know about the wound types and how to ask about the blood type, and if they've found other people's DNA under the nails, do we have bruises, broken bones, and what is about rigor mortis and how many cigar ashes could we find beside the hedge. This storyline is rather incomplete, Duo!
I think she broke the bottle and used it as a knife. They took the knife off her in airport security, so she bought a bottle of whiskey in duty free, drank the contents, which made her a bit crazy. So she whacked the bottle off the wall and attacked the pilot with it
Probably not. I think when you say "had" used that would be translated in the traspassato congiuntivo-- "avesse usato." Think about it-- if it were NOT a thing in doubt but a certainty you would say Lei ha usato for "she used a knife,") and Lei AVEVA usato for "she HAD used a knife."
I used 'I am not sure if she used a knife a bottle' and it is wrong, OK, technically I know the phrase is I don't know, but I was trying to place it in a context when you wouldn't be sure because the sentance gives you a choice of a knife or a bottle. Surely you would be uncertain?