"Clearly, it's an inside job"
Yes, and clearly what a devious, well-organized plot it was. They got this super-trained assassin, Crooks, to crawl along a roof where everybody could see him and let him get off eight shots.
I mean why hire expert marksmen to do the job when you can get an untrained, mentally ill loner with negligible stealth skills to make an attempt?
It was just a massive screwup by the SS.....nothing more, nothing less. No evil plotting involved.
This ignores the sound analysis that showed two shooters.
Transit time from the bullet arriving (sonic 'crack') and the sound of the rifle discharging is different, showing two rifles involved (the bullet gets there first). If one shooter was located beneath or above and behind crooks, along a very similar azimuth from the stage, trajectories might not sort out the difference. It would be ideal to have the 'pro' located near the patsy, azimuth wise, and if dressed as one of the myriad different groups of LEOs present, they could just walk away.
As for finding 8 cartridge cases on the roof, expended .223 (or 5.56) brass is common as cat crap. Google it if you don't believe me, it is sold in bulk, and often found at rifle ranges. It is doubtful that Crooks reloaded, so brass from his rifle may have been available at the range where he shot.
But with a tendency to not ask all the questions (just stop with the 'answers' that fulfill the narrative), that brass could have been fired by most anyone, anywhere, any time, and there were lots of people who shoot it there that day on the security crew. While hardly sufficient, IMO, as evidence, some rifles will leave characteristic deformations or markings on expended cartridge cases, either by the location and depth of penetration of the firing pin, the extractor, or by the process of extraction. So much so that some states required cartridge cases to be filed when purchasing a firearm, and some I bought in ND which were NIB and obviously from states which restricted magazine size, came from the factory with an expended case in an envelope to file with TPTB. They were sold by an FFL here because the whole sale process in ND was much simpler.
With that in mind, has any analysis of the cartridge cases allegedly from Crooks' rifle been conducted with cases obtained by test firing that rifle?
Have the head stamps on the cartridge cases been checked?
Are they even from the same manufacturer?
Have any recovered bullets (have any even been recovered) been subjected to ballistic analysis with bullets fired from Crooks' rifle for comparison?
Or are we just taking their word for everything, the word of the SS people who have been caught lying before Congress and the world?