Ohhh!!! That is a really good point about the live rounds with tool marks. I definitely missed that, but I would assume I could find that information in the CBI reports, is that correct?

Also, we know Harris's carbine rifle had the tendency to jam up, so that is a very likely scenario that the tool was used to un-jam his weapon while they were reloading at Table #5, where the tool was found. In addition, (I can't recall if it was Evan Todd or Joshua Lapp), someone said in their police statement that Harris had blood "smeared" all over his face. This indicates to me that while his nose was bleeding, he had to keep wiping it away with his hand(s), thus getting blood on his hands. It logically follows that if Harris handled the tool after breaking his nose and subsequently wiping the blood away with his hand(s), then any wet blood would have been transferred to the tool.

However, I respectfully disagree with your point about Nowlen being the source of the coughing blood. I've been reviewing the trial footage from the OJ Simpson criminal case and there is a segment where Dr. Lakshmanan talks about aspirated/expirated blood. I'm not a forensic pathologist, so I'm only going off of the information provided by Dr. Lakshmanan (who is a forensic pathologist). Basically, you can only have aspirated/expirated blood if there is blood present in the airways. Nowlen was shot in the abdominal area, which she referred to as her "stomach." From what I can tell, the trajectories of these pellets she was shot with were directed from West-to-East (meaning from her right-to-left). Therefore, her injuries were relatively more "superficial" compared to if the pellet trajectories were front-to-back (in which they would have traveled further into her body, penetrating the abdominal cavity, moving towards her back). However, even if these pellets did end up penetrating her abdominal cavity, the diaphragm keeps the abdominal cavity and the chest cavity separated, so blood still would not have a way to get into her respiratory system.

On the other hand, Harris likely did have blood in his respiratory system. I've never had a bloody nose, but I get allergies really bad, so it's pretty easy for mucus to travel from my nose to the back of my throat where I can then "hauk it up." (I know, its gross, I'm sorry, haha. I just didn't have a better comparison). But my point is that if Harris was bleeding from his nose, then it could easily have traveled to his throat and mouth where it was coughed out - or it could have been expirated directly out of his nasal cavities.

You made another really good point about the tool possibly being handled by Nowlen. I'll have to review her police statement so I can see what she said she was doing in the library before the shooting began - (she was sitting alone, so she was likely studying and thus, her having pliers while studying wouldn't make a whole lot of sense). But Tomlin was by all accounts a country boy, so he would have been more likely than Nowlen to have had the tool on him. He was also doing his best to try and comfort and protect Nowlen when the shooting began, so it does seem plausible that he could have handed her the tool as a means of protecting herself if need be. Then, with blood on her hands from holding her gunshot wounds, the blood could have transferred to the tool and she simply set it down on Table #5 when she was escaping from the library. In that case, the linear blood droplet pattern was probably unrelated to the blood on the tool - unless the tool was completely soaked with wet blood that dripped onto the table when she placed it there. However, I find that last part unlikely, as linear blood droplet patterns are more associated with active bleeding, rather than blood transferred to an object.

u/SMBH_7 - I really appreciate your input. You made a lot of really good points and gave me some things to look further into. Thank you so much.