Live updates: FBI, Secret Service investigating motive of Trump shooting suspect

Democratic Rep. Ritchie Torres of New York and Republican Rep. Mike Lawler of New York are planning on introducing bipartisan legislation to provide Trump, Mr. Biden and RFK, Jr., with enhanced Secret Service protection, according to Torres's office. 

"Last night's attempted assassination of former President Trump was a dark moment in our nation's history," the two congressmen said in a joint statement. "As reports continue to emerge, it's clear that more protection is needed for all major candidates for president. That's why we're planning on introducing bipartisan legislation providing President Joe Biden, former President Donald Trump, and presidential candidate Robert Kennedy, Jr., with enhanced Secret Service protection. Anything less would be a disservice to our democracy."

The RFK Jr. campaign has long been asking for Secret Service protection. His father, Robert F. Kennedy, was assassinated during the 1968 Democratic presidential primaries. 

— Nidia Cavazos and Kathryn Watson 

Vice President Kamala Harris was scheduled to campaign on reproductive rights Tuesday in Palm Beach County, Trump's backyard. 

But a Biden-Harris campaign official said the event has been canceled following Sunday's shooting. Sunday night, Harris said she was "relieved" Trump wasn't seriously injured. 

"Violence such as this has no place in our nation," she said in a statement. "We must all condemn this abhorrent act and do our part to ensure that it does not lead to more violence."

Two law enforcement sources told CBS News that the suspect was spotted outside the security perimeter as people were filing into the rally, and he was reported by a bystander to the Butler County Sheriff's Office. He was identified as a suspicious person by police, the sources said. 

The sources said officials momentarily lost track of the suspect. Six minutes after Trump started talking, the suspect crawled up the side of the shed, and "popped up" on the roof, then immediately began shooting, the law enforcement sources said. He was lying flat on the shed — not walking or standing. There was very little time that passed here between when he popped up and when shots rang out. 

The suspect fired 6-8 rounds using a semi-automatic AR-15, approximately 400 feet from the podium. 

Secret Service counter sniper teams "had him" within seconds — the threat was neutralized almost immediately after shots were fired, the law enforcement sources said. 

— Nicole Sganga and Pat Milton

According to multiple law enforcement officials, the shooter was armed with a semi-automatic AR-15. ATF is tracing the weapon. 

The gunman was on top of a shed outside the security perimeter set up by the Secret Service, and opened fire from about 400 feet away from the stage, law enforcement sources said. 

Read more here.

Details about the shooter, Thomas Crooks, began surfacing after the FBI identified him as the subject involved in the assassination attempt. He was a 2022 graduate of Bethel Park High School. 

A law enforcement official told CBS News that the Secret Service and FBI are investigating the suspect's background and speaking with his family. 

No foreign terrorism ties are known to Crooks at this time and the suspect was not on law enforcement's radar, a law enforcement official said. 

There was no indication that Crooks had a connection to any military branch, officials confirmed to CBS News. 

Crooks' political leanings were not immediately clear. Records show he was registered as a Republican voter in Pennsylvania but previously made a $15 donation to a Democratic-aligned group, CBS Pittsburgh station KDKA reported.

The Secret Service issued a statement on Sunday morning saying it was "untrue" that a member of former President Donald Trump's team had requested more Secret Service protection.

"There's an untrue assertion that a member of the former President's team requested additional security resources & that those were rebuffed. This is absolutely false. In fact, we added protective resources & technology & capabilities as part of the increased campaign travel" protocols, the Secret Service said in a statement. 

Trump has had a Secret Service detail since 2016, and all former presidents and their spouses have Secret Service protection for the remainder of their lives, unless that person declines. Trump was given additional protection in June as part of the protocol for the process for a presumptive presidential nominee. Those additional protections include additional manpower, counter sniper, drones and robotic dogs. 

Trump campaign senior advisers Susie Wiles and Chris LaCivita instructed campaign staff in a memo to stay away from offices in Washington, D.C. and Palm Beach, Florida, after Saturday night's assassination attempt on former President Donald Trump while the locations are assessed and security enhanced. 

"Our highest priority is to keep all of you on this staff safe," the advisers said in the memo, which noted that the RNC Convention in Milwaukee will continue as planned.

"We also urge you to recognize the political polarization in this heated election," the managers said, instructing staff not to comment publicly on the incident. "We condemn all forms of violence, and will not tolerate dangerous rhetoric on social media."

House Speaker Mike Johnson said Sunday on NBC's Today that he spoke with Homeland Security Secretary Alejandro Mayorkas last night, but meanwhile "everyone needs to turn the rhetoric down."

"We can have heated political discourse and debates but it shouldn't be personal and we shouldn't be targeting people," Johnson said. "I mean, look, President Biden himself said in recent days, it's time to put the bullseye on Trump. I mean, I know that he didn't mean what is being implied there, but that kind of language on either side should be called out and we have to make clear that this is part of our system. We can have vigorous debate, but it needs to end there."

Johnson has called for the House to conduct an investigation into the shooting. 

Law enforcement officials on Sunday swarmed the home believed to be connected with the shooter in the assassination attempt of former President Donald Trump.

Public records show the home is that of 20-year-old Thomas Crooks, who federal law enforcement officials identified as the shooter who opened fire at the rally in Butler on Saturday evening.

One neighbor, who lives only a few homes down the road from the gunman, told CBS Pittsburgh that police evacuated her home in the middle of the night. She was told noon on Sunday was the earliest she could be allowed back into her home.

"They asked us to leave our house. They told us it was a state of emergency, no warning, just a knock on the door in the middle of the night," Kelly Little said. "They told us we could come back in a couple of hours, likely." 

Read more on CBS Pittsburgh.

 Former President Donald Trump posted on Truth Social early Sunday that Americans need to "remain resilient in our Faith and Defiant in the face of Wickedness," hours after a gunman opened fire at his Pennsylvania rally, leaving him injured. 

"In this moment, it is more important than ever that we stand United, and show our True Character as Americans, remaining Strong and Determined, and not allowing Evil to Win," Trump wrote. "I truly love our Country, and love you all, and look forward to speaking to our Great Nation this week from Wisconsin."

Trump is set to speak Thursday at the Republican National Convention in Milwaukee.