A witness to the shooting at Donald Trump's rally in Butler, Pennsylvania, says he saw the gunman on a roof and flagged the suspect to police right before shots rang out.

Adding:  BREAKING! Police Officer Confronted Shooter Before He Fired at Trump, AP Sources Say

Associated Press reports that not long before shots rang out, rally goers noticed a man climbing to the top of a nearby building and warned local law enforcement, according to two law enforcement officials.

One officer climbed to the roof and encountered Crooks, who pointed his rifle at the officer. The officer retreated down the ladder, and Crooks quickly took a shot toward former President Donald Trump. That's when U.S. Secret Service counter snipers shot him, said the officials, who spoke to The Associated Press on condition of anonymity to discuss an ongoing investigation.

adding:

The firearm recovered at the scene was legally purchased by the suspect's father, an urgent trace conducted by ATF found, according to multiple law enforcement sources. A source who has been briefed said the gun was an AR-15 style rifle that was purchased in 2013.

Crooks allegedly fired as many as eight rounds from a rooftop 200-300 yards away, other sources said.

'Lonely' and 'quiet'

Former classmates of the suspected shooter described him to ABC News as a student who was "quiet" and did not have many friends,.

"He was somebody who came across as lonely a lot," said Jameson Myers, who said he attended both elementary and high school with the suspect.

Myers said that Crooks "tended to be more of an interesting one” and described him as "more socially reserved" and someone who "didn't have a ton of friends." But he said he never heard Crooks discuss politics or, specifically, Donald Trump.

“I was friends with him- he never acted, like, by any means a political revolutionary,” Myers said, noting he was a fan of "Star Wars" and “was a very nice, even sweet guy from what I knew.”

Myers said that Crooks tried to join the high school's rifle team but was rejected and asked not to return.

“He didn't just not make the team, he was asked not to come back because how bad of a shot he was, it was considered like, dangerous,” said Myers.

Another member of the team, who asked not to be named, told ABC News that there was a view that Crooks "wasn't really fit for the rifle team."

"He also shot terrible," the team member added.

The coach of the team at the time declined to comment and referred questions to the school district. A spokesman for the schools did not reply.

above partial from:

https://abcnews.go.com/Politics/trump-rally-shooting-suspect-fbi-names-pennsylvania-man/story?id=111921870

This video, CBS News

https://t.co/nSwmWOaGFa

https://x.com/CBSNews/status/1812302268080730562?ref_src=twsrc%5Etfw%7Ctwcamp%5Etweetembed%7Ctwterm%5E1812302268080730562%7Ctwgr%5E2be6ea9495fd50e61231875f33cd571afac3e17d%7Ctwcon%5Es1_&ref_url=http%3A%2F%2Fwww.godlikeproductions.com%2Fforum1%2Fmessage5756491%2Fpg1