I'm not a gun guy and I've been lazy (I only read the very short article) but to me it seems like a 10/10 "What the fuck were they thinking?" screw up by the Secret Service.
Sniper shot at former President Donald Trump from 130 yards away on roof of manufacturing plant
Should’ve used an AR15
This is why civilians need access to automatic weapons
Nothing some homemodding can't fix
a DP-28 would've ruled
Should have aimed or something (an "AR-15 style" rifle is probably sufficient caliber to kill Trump if you hit center mass)
Whoops
That's more of a schoolboy's weapon though