Shots fired at Trump rally, page-1760

The multitude of evidence that we actually know as fact
He was seen climbing the ladder to the roof - true
He was seen on the roof with a rifle - true
There was only one defense sniper on duty
There was no one assigned to the other roofs ( as far as we know)
He shot a number of times before the defense sniper fired back - true
The comic caper on the stage was real IrrelevantSeems we know very little at this stage but don't let that stop you

I'm more interested in - for starters:

• what rifle was used
• where did it come from
• how long had he had it
• was it legally purchased
• where did he train
• who did he train with
• any evidence of his marksmanship