[janetjanet998]

This article from last night says after the shooting
Either this article is not correct or he made two separate calls

https://www.msn.com/en-ie/news/world/dad-of-trump-shooter-called-police-after-attack-with-concerns-that-his-son-and-gun-were-missing-report-says/ar-BB1q5NE2

Matthew Crooks realized his 20-year-old son, Thomas Matthew Crooks, and an AR-style rifle were missing shortly after shots were fired at the former president at a campaign rally on Saturday in Butler, Pennsylvania. Three senior law enforcement officials told NBC News that the father then called police

[dragnet2]

I would guess it’s possible dad called 911 due to his son telling him his plans from the rally venue...Saying his last goodbye etc...

I dunno. Just speculating...

[alternatives?]

“Matthew Crooks realized his 20-year-old son, Thomas Matthew Crooks, and an AR-style rifle were missing shortly after shots were fired at the former president at a campaign rally on Saturday in Butler, Pennsylvania. Three senior law enforcement officials told NBC News that the father then called police.”

Good post. Eliminates a lot of speculation. Adds some others.