>Who is Delaney Tarr?
Judging by the photos and the fact that she's on an extended "field trip," I'd guess and say that she's a young radical who became energized last week and is using her dead classmates to push politics and social bullshit. She's using those dead bodies as a stepping stool to put herself in the spotlight.
Yep.
What are the odds that not only was she nowhere even close to where the shooting took place, but she doesn't even personally know any of the dead students?
My high school had around that many students as well. While you knew a lot of the people in your grade, and some ahead and behind you, you still only knew about maybe 10-15% of the entire student body, and actually socialized with far fewer then that percentage.