So it may be hard to watch and get through because it can be annoying, but a witness claims she saw a black motorcycle pull in where only cop cars were allowed outside of the building the shooter was apparently on. The rider was wearing black, skinny jeans, and a don't tread on me flag around the neck - witness makes comments that this rider could be trying to look like "one of us". Witness mentions a door to the building that was previously closed is now wide open. Witness mentions police storm the building through door.

Full interview here : https://www.youtube.com/watch?v=QvTT27uq7DM

Shorter more annoying video but shows the motorcycle was still there the next day. : https://www.youtube.com/watch?v=uRtf_ut0_3g

I have seen the water tower theory as well and it's worth noting that the view from the shorter video of the open door and motorcycle is on the same side where the water tower is, Meridian Dr. Just making a note of location. There is a road that leads right up to the water tower from Meridian Dr.