Trump shot at rally in failed assassination attempt. Here's what we know.

Former President Donald Trump was shot and injured in an assassination attempt on Saturday night that also killed a spectator and critically injured two others. Snipers killed the shooter, a 20-year-old man, after he fired eight rounds at the rally in Butler , Pennsylvania.

The former president could be seen touching his ear as the shooting unfolded before he was shielded by Secret Service and whisked offstage — with blood on his face — and into an SUV to safety. Trump said in a social media post that a bullet pierced the upper part of his right ear.

"I knew immediately that something was wrong in that I heard a whizzing sound, shots, and immediately felt the bullet ripping through the skin," he said. "Much bleeding took place, so I realized then what was happening."

The Secret Service later said Trump was safe, and that he went to a local hospital and left hours later.

The gunman was fatally shot by a Secret Service sniper, authorities said.

FBI officials said the shooter appeared to be a lone actor, and the incident was being investigated as an assassination attempt and as a potential case of domestic terrorism.

Who shot Donald Trump?

The FBI identified the shooter early Sunday as 20-year-old Thomas Matthew Crooks, of Bethel Park, Pennsylvania. The town in Allegheny County, just outside Pittsburgh, is home to about 30,000 people.

Law enforcement officials say he was armed with a semiautomatic AR-style rifle. Two law enforcement sources say the gun was legally purchased by and registered to the shooter's father, Matthew Crooks.

Crooks was a 2022 graduate of Bethel Park High School  School officials pledged to work with law enforcement investigating the shooting, and offered condolences to those affected by the attack.

Former classmate Jameson Myers, a member of the school's varsity rifle team, told CBS News that Crooks had tried out for the team freshman year but did not make the junior varsity roster and did not return to try out for the team in subsequent years.

He called Crooks a "nice kid who never talked poorly of anyone," adding, "I never have thought him capable of anything I've seen him do in the last few days."

Another classmate, Jason Koehler, had a somewhat different view, telling KDKA's Megan Schiller that Crooks was a loner who was bullied for his appearance and wore camo/hunting outfits in class. He said Crooks would often sit in the cafeteria alone before class. He also said Crooks was very COVID-conscious and wore a surgical mask long after they were required.

But Mark Sigafoos, who graduated with Crooks and had two classes with him senior year, said he never saw him bullied. He described Crooks as super smart and approachable, engaged in class and always volunteering answers.

"This is one of the things that is being misconstrued — he was not some type of loner trenchcoat wearer. And I will say he was definitely nerdy, for sure, but he never gave off that he was creepy or like a school shooter," Sigafoos said. "He seemed like he wouldn't hurt a fly."

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.

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

A law enforcement official said early Sunday that the Secret Service and the FBI are investigating the suspect's background and speaking with his family. The FBI has secured his home and federal law enforcement is searching his family's residence in suburban Pittsburgh, the law enforcement official said. His family is cooperating with investigators, an FBI official said.

Law enforcement sources told CBS News on Sunday that suspicious devices were found in the gunman's vehicle. The gunman also had with him a piece of commercially available equipment that appeared capable of initiating the devices. Bomb technicians called to the scene were involved in securing and investigating the devices.

Do we know the motive for the assassination attempt?

In a news conference late Saturday night, Kevin Rojek, special agent in charge of the FBI Pittsburgh office, refused to speculate on a possible motive.

"Right now, we're tracking down all leads, and doing all interviews, and tracking anything that we can regarding suspicious locations, vehicles ... that's all related to this event, but I can't confirm or deny anything beyond that," Rojek said.

A law enforcement official said early Sunday that no foreign terrorism ties were known and the suspect was not on the radar of law enforcement, although they were still running his name down.

The FBI says investigators are combing through his social media postings and emails, but that so far they have found nothing to lead them to a motive. They said are not seeing anything threatening in his postings so far.

Investigators also have his cellphone, which was sent to the FBI lab in Quantico, Virginia, for analysis.

The FBI is leading the investigation, with assistance from the Secret Service and state and local agencies.

How is Trump now?

The Trump campaign said in a statement Saturday that the former president was 'fine." He was taken to a local hospital and left a few hours later.

In a post on Truth Social Saturday night, Trump described his injuries: "I was shot with a bullet that pierced the upper part of my right ear. I knew immediately that something was wrong in that I heard a whizzing sound, shots, and immediately felt the bullet ripping through the skin. Much bleeding took place, so I realized then what was happening. GOD BLESS AMERICA!"

He thanked the Secret Service and other law enforcement agencies for their rapid response, and extended condolences to the family of the man who was killed.

He posted on Truth Social early Sunday that Americans need to "remain resilient in our Faith and Defiant in the face of Wickedness."

"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," where the Republican National Convention begins Monday.

Video posted by a Trump aide to social media early Sunday morning showed him walking down the steps of his plane unaided after landing at Newark Liberty International Airport in New Jersey.

According to a source familiar with the matter, early Sunday evening, Trump landed in Milwaukee, where Republicans are gathering to formally nominate him for president. Earlier Sunday, Trump wrote on Truth Social that he had decided against delaying his arrival in the city, saying he, "cannot allow a 'shooter,' or potential assassin, to force change to scheduling, or anything else."

Where was the Trump rally and how far away was the shooter?

The rally on Saturday was in Butler, Pennsylvania, which is north of Pittsburgh and is the county seat of Butler County.

The gunman was on the roof of a shed, outside the rally's security perimeter set up by the Secret Service, and opened fire from about 400 feet away from the stage where Trump was speaking, law enforcement sources said.

Two law enforcement sources told CBS News that the shooter 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.

An armed municipal officer with Butler Township encountered the gunman before the shooting, Butler County Sheriff Michael Sloupe confirmed to CBS News. The officer and others had been previously alerted to a suspicious person and began searching for him right away, Sloupe told CBS Pittsburgh reporter Jen Borrasso.

At some point, the officer was hoisted by another officer onto the roof of the building where the shooter was in position. The shooter focused his rifle towards the officer, who let go and fell off the roof. Then the shooter began firing into the crowd, according to Sloupe.

The gunman fired 6 to 8 rounds using a semiautomatic AR-style rifle from his position approximately 400 feet from the podium, before he was shot and killed by a Secret Service sniper team.

Rojek, with the FBI, called it "surprising" that the gunman was able to fire multiple shots.

"It is incredibly difficult to have a venue open to the public, and to secure that against any possible threat, against a very determined attacker," Pennsylvania State Police Lt. Col. George Bivens said of the Secret Service. "That's a huge lift to try and do it."

Who was the rally victim who was fatally shot?

The spectator who was killed has been identified as Corey Comperatore , a 50-year-old man who was shot while attempting to shield his family from the gunfire, Pennsylvania Gov. Josh Shapiro said at a news conference Sunday.

"Corey was the very best of us," Shapiro said. "Corey died a hero. Corey dove on his family to protect them last night. Corey was a 'girl dad.' Corey was a firefighter. Corey went to church every Sunday. Corey loved his community."

Pennsylvania State Rep. Marci Mustello called Comperatore "a devoted public servant, having served as the fire chief for Buffalo Township Fire Company, and he was a cherished member of our community in Butler County."

"His commitment to his wife and two daughters, and his unwavering dedication to his role as a fire chief exemplified his remarkable character," Mustello said. "My heart breaks for his loved ones during this incredibly difficult time, and I join the community in mourning his loss. A true American hero, Corey sacrificed his life to protect his family."

"May Corey Comperatore's memory be a blessing and a reminder of the selfless service he provided to us all."

The two spectators who were wounded have been identified as 57-year-old David Dutch, of New Kensington, Pennsylvania, and James Copenhaver, 74, of Moon Township, Pennsylvania. Both were listed in critical but stable condition Sunday.

What did Biden say about the shooting?

President Biden first responded to the shooting in a statement saying he was grateful to hear that Trump was safe and doing well.

"Jill and I are grateful to the Secret Service for getting him to safety," he said. "There's no place for this kind of violence in America. We must unite as one nation to condemn it."

He then addressed the nation shortly after 8 p.m. ET Saturday, saying "there is no place for this kind of violence in America."

"It's sick. It's sick," Mr. Biden said. "It's one of the reasons why we have to unite this country. We cannot allow for this to be happening. We cannot be like this. We cannot condone this."

On Sunday, Biden made brief remarks at the White House, saying he was "sincerely grateful" that Trump is doing well, adding that he spoke with the former president on Saturday night. He characterized the call as a "short, good" conversation, and said he would address the nation from the Oval Office at 8 p.m. Sunday.

He has been getting briefed by top officials and said he has ordered an independent review of the security and events at the Pennsylvania rally to determine what went wrong.

Mr. Biden also called for unity in the wake of the assassination attempt and denounced political violence.

"There's no place in America for this kind of violence, or any violence for that matter," the president said. "An assassination attempt is contrary to everything we stand for as a nation. It's not who we are as a nation."

The president said unity is the "most elusive goal of all" and added that "nothing is more important than that right now. Unity."

A Biden campaign official said Saturday that the campaign was pausing all outbound communications and working to take down their television ads as quickly as possible.

Robert Costa, Pat Milton, Andy Triay, Arden Farhi, Fin Gomez, Aaron Navarro, Sara Cook and other CBS News staff contributed reporting.