Clarifying, the police sharpshooter fired first, at the assassin, but did not stop the threat. I don’t mean the sharpshooter fired at Trump.
The closer sniper appears to raise his head to spot the shooter. (The chances of the shooter appearing over the ridgeline of the building already in the sniper’s ‘scope are nil.) Spotting the shooter the closer sniper adjusts and goes back to the ‘scope, but BOTH snipers flinch at the 1st 3 shots. The camera pans left so we don’t see the snipers return fire, but we hear other shots begin with a somewhat different sound and a faster rate.
In a different vid taken near the AG building one can hear the shooter’s 3 shots again, then 5 rapid, more powerful shots, a slight delay and a not-as-loud shot, another longer delay, and yet another not-as-loud shot.
https://www.cnn.com/2024/07/13/politics/video/shooting-video-gunman-trump-digvid
There is also this vid describing sniper target acquisition:
https://www.cnn.com/2024/07/14/politics/video/trump-shooting-security-failure-mills-ldn-digvid
It’s not “instant”.
So... I’m going to take back something I posted earlier — based on the video and especially the acoustics from the 1st link in this post, I don’t think those 5 rapid shots came from the snipers near Trump, and those shots were not the shooter. I would guess a different “asset” nearer the building spotted the shooter popping up, got sights on him, and fired those 5 shots, taking the would be assassin down. The last two shots came from yet another LEO or SS (maybe the shooter twitched?)
In this scenario the snipers on the roof near Trump did not fire the grouping of 5 shots because the shooter had already been hit by the time they recovered and got dialed in / crosshairs on the target.