Total speculation and MOO.
I'm not of the conspiracy mind, however, I've really been pondering a lot of things that just don't "add up" through the very scant amount of information we have thus far.
One thing that did occur to me today, as a possible explanation of the location of the second mask and knife:
If after leaving Theater 9, JH didn't exit the building, as we could naturally suppose he did. Instead he "exited" from Theater 9 and following with news reports have said, went to Theater 8. But, instead of going outside the building, he traveled inside the building via an employee or emergency corridor or hallway of some sort.
This would give credence to the guy's report that he let the two girls back into theater 9 and then held the door closed so that the shooter couldn't get inside. If it had of been an exit door to the outside of the building, there would only have been the need to shut the door if it were operating effectively since it would have automatically locked. Furthermore, he wouldn't have had to "hold" it shut after it closing because there wouldn't have been a handle for JH to hold onto to try to pull the door open. Thus, no struggle to "keep" it closed.
After not being able to access Theater 8, JH may have continued down that hallway to the end of the theater complex, thus eventually exiting into the "outside" of the theater at the end of the building. Here, after finishing his planned assault and being hot in the mask, he may have dropped both it and the bloody knife on the sidewalk and continued to his car. I know that there are reports that he had the mask either with or on him at the time. Perhaps there was another one in the car as a backup. He may have been concerned that once the respirator was activated, it might not work, thus bringing along a spare for some reason. Doesn't necessarily make sense, but then again all of us do things that others looking in would find odd or nonsensical.
Suppose that once he reappeared outside, other witnesses/victims (from the blood splatter it would have to be a more intense wound than the two girls mentioned prior), started exiting from the theater. Thus, the comment from victims that he was shooting people as they came out of the exit. Perhaps he then shot one or more people on that back sidewalk. That would explain the blood starting partway up the sidewalk back INTO the theater instead of out. It would also explain the faint bloody footprints that are alongside the wall leading back into the theater 9. The blood seems, to my uneducated min, to build in amount up into the door with bloody handprints on the door as the victims tried to rush BACK into the theater to escape the shooter if he came back inside. That would explain, perhaps, the gun by the door. He may have put it there if he was going to check for anyone else in there and tried to open the door. Maybe they had closed it on their way in?
ALL speculation. But, it's really been bothering me. Plus, the requests for the floor plans have been denied, thus giving me reason to believe that the floor plan of the theater holds something essential to the investigation.
I'm still having a very difficult time buying the story we've been give thus far and integrating that into a lone gunman. However, something like this would have made it more feasible at least.
And, a different take on the same scenario. Leave out the encountering anyone along the back of the building and shooting them...
Also, as far as the time line... There have been some people adding things up and saying that JH would have been in his car already (if they were adding things up correctly) by the time the cops were surrounding theatre 9.
This would explain the comment of one cop seeing a man in a gas mask, Sable side, and then not long after them spotting JH in his car. If he was traveling down the interior hallway at the same time the first LE went along the backside of the theater, a LE may have spotted him just after coming out the exit door at the end of the building -- i.e. suspect in a gas mask. JH could have continued on to his car (where he was apprehended by officers that had come BACK out of the back of the theater after first passing his car.
Yes, truly speculation. But, then again, at this point in the game of this case, I'm not sure anymore what all isn't speculation!
Again, just random thoughts and opinions.