Maybe he could present this to someone who can verify and corroborate his claims.

Not...us, the brain-rotted denizens of the most soul-numbing recesses of the internet.

While it's not outside the realm of possibility that the shooter did not work alone, this is baseless conspiratorial nonsense that's an even balance of desperate grasping and outright falsehoods.

There is zero *need* for anyone else on-site for a perfectly coherent explanation of events.