I'm here, but don't know the answer to your question. Stlnative will need to answer, or one of the others who has majored in this aspect.
Tell me, please, if your're wondering if it could be a tourniquet, what would be the story there. We know what the purpose of a tourniquet is...to slow or stop bleeding from a wound. The wound she had was a terrible head wound, little or no external bleeding, right?
Are you saying the perp could have tried to apply a tourniquet after he horribly injures her head???
I'm just trying to understand. I do pay attention to your posts, always.
I'm not saying that it was in any way a touniquet...only that it might have been the lightbulb that made Karr think of it. It goes to his background...Say Red Cross certified rather than a military background.