*sigh*
Small caliber semi-auto handgun.
Probably from the stands to his right rear (viewers left). We'll have to wait for video from or of that location (and there will be at least some) to confirm what happened to the flurry of follow up rounds that were fired. It's possible those were fired as the shooter was being tackled by bystanders.
Not a professional.
Dunno how many realize this but that shooter just made a living martyr out of that PoS.
Depends on who was responsible for crowd control at the site (usually local/state PD handles that part).
The Secret Service detail concentrates on their principle. They do have snipers on most scenes (all outdoor ones).
But if the shooter was in the audience (as I suspect) a sniper may not have had a clear shot.
@voltronic @Render this timeline is about to get a whole lot dumber…..