I’ve droned all of the rooftops on AGR and building 6 does have some funky black marks on the ridge cap that none of the other rooftops have, but I think it’s probably attributed to something less nefarious. They’re clear on my drone footage but I don’t know how to pull a screenshot from it so I take a picture with my cell phone which kills the resolution. The other rooftops have the black marks down by the gutters.
I’m pretty convinced this is solved and “Sniper Greg” (as you call him) needs to be hauled in and waterboarded before he mysteriously dies in some unorthodox fashion.