Watch: How Trump rally shooting unfoldedpublished at 07:27 British Summer Time 14 July
Here's what we know so far about the chaos that unfolded at Donald Trump's rally, in under one minute.
Donald Trump arrived at the Republican National Convention in Milwaukee for his first public appearance since he survived an assassination attempt two days ago
He had a large bandage on his right ear, which was injured when an attacker opened fire at a political rally
The leading Republican candidate became the party's official nominee earlier today, after a formal counting of the delegates at the convention
The former president named JD Vance, the senator from Ohio, to be his running mate and vice-president if he returns to the White House
Vance was once a Trump critic, but has since become one of the candidate's most trusted defenders on Capitol Hill and in the media
Trump also enjoyed a big legal win earlier today, after a judge in Florida threw out the classified documents case against him
Meanwhile, the fallout from Saturday's shooting continues - the US Homeland Security secretary says the gunman should never have had a direct line of sight
Edited by Brandon Livesay, at the convention
Here's what we know so far about the chaos that unfolded at Donald Trump's rally, in under one minute.
Former US president Donald Trump was rushed off stage during a rally in Pennsylvania after a gunman fired multiple rounds from an “elevated position” a few hours ago.
If you’ve just joined us, here's a quick recap on what we know about the shooting so far:
Our colleagues at BBC Verify have analysed images from the scene to determine how close the gunman got to the former US president.
More from the FBI statement which has identified the gunman at the Trump rally as Thomas Matthew Crooks.
It says Crooks was from Bethel Park of Pennsylvania.
This is a town about 70km (43 miles) or an hour's drive from Butler, the site of the attempted assassination.
"This remains an active and ongoing investigation, and anyone with information that may assist with the investigation is encouraged to submit photos or videos online," the statement added.
The man who is suspected of attempting to kill Donald Trump is 20-year-old Thomas Matthew Crooks, according to a FBI statement released a short while ago.
Stay with us as we bring you more from the statement.
The FBI says it is unable to release the name of the man who is suspected of shooting Trump at this time.
They say the man has been “tentatively identified” but that DNA and biometrics tests must be done to conclusively confirm his identity.
“We are not prepared at this time to release the identity of the potential shooter. We are in the process of doing the confirmation. Once we get the confirmation we will release the name officially to the press,” FBI special agent Kevin Rojek said.
“It’s a matter of doing biometric confirmations. There was no identification on the individual. We are looking at photographs right now. We are trying to run his DNA and get biometric confirmation."
The FBI also could not immediately ascertain what type of firearm was used and how many shots were fired.
Donald Trump was injured after a gunman opened fire during a campaign rally in Pennsylvania. If you are just joining us, here is a quick wrap of everything we know so far:
Brajesh Upadhyay
BBC News, Washington
The attack on Donald Trump at his campaign rally in Pennsylvania has put the spotlight on the apparent security lapse and some are also pointing fingers at the Secret Service for letting an attacker slip by.
The former president himself did thank the Secret Service and other law enforcement "for their rapid response on the shooting that just took place".
But questions are being raised and some are calling it a “complete failure” on the part of the Secret Service.
US House Speaker Speaker Mike Johnson vowed that the House will conduct a full investigation.
In a post on X, formerly Twitter, the speaker said: "The American people deserve to know the truth.
"We will have Secret Service Director Kimberly Cheatle and other appropriate officials from DHS and the FBI appear for a hearing before our committees ASAP."
The Secret Service has agreed to brief the House Oversight Committee about the attack, a spokesperson confirmed to The Hill.
"He (Trump) does get a very robust former protection detail that is with him all the time. But he doesn't necessarily get all of the different assets that are available. So, I think that there are some aspects of this incident that are going to be investigated," retired Secret Service Supervisor Bobby McDonald told Reuters.
“The Secret Service will now look at what happened and how that they can again develop and continue to enhance their protective methodologies to make sure that things like this do not happen in the future.”
At the start of the press conference, FBI field officer Kevin Rojek confirmed that the incident was being treated as an assassination attempt.
"This evening we had what we're calling an assassination attempt on our former president Donald J Trump," he said.
"It's still an active crime scene," he added, pointing out that they had a number of agents on the scene investigating the incident.
During the news conference, the FBI confirmed law enforcement did not know there was a person on the roof of a building nearby Donald Trump's rally until shots were fired.
"So that is the assessment this time," said FBI special agent Kevin Rojek when asked by a reporter if they didn't know about the sniper's position beforehand.
An eyewitness told the BBC that several minutes before the shooting occurred, he had spotted a man on the roof of a nearby building. He had tried to inform the police for "three to four minutes", but thought they probably could not see the gunman because of the slope of the roof.
The news conference about the shooting at Donald Trump's rally has now ended.
Stick with us as we bring you all the latest updates.
All three victims from the rally - two who were wounded and one who was killed - are adult males, law enforcement says.
Many of the questions at this news conference specifically about the response to the gunman and whether it was quick enough are being batted away as questions for the US Secret Service.
The FBI special agent speaking here, Kevin Rojek, says that the Secret Service were not able to be part of this news conference.
Law enforcement say they could release the name of a suspected shooter within the next few hours.
Law enforcement say one shooter has been "tentatively identified", but do not give a name or any identifying details.
It is difficult to hear questions from reporters on the live feed, but Lt Col George Bivens appears to be answering questions about the speed of the police response.
He says law enforcement responded to several reports of suspicious activity at the rally.
Lt. Col George Bivens from the Pennsylvania State Police said officers at the scene had acted "heroically" to respond to the shooter.
He says there is no reason to believe there is any further "existing threat out there".
The FBI says they are not prepared to identify the attacker and they have not yet identified a motive.
The attacker was not carrying any ID documents, so officials are waiting for DNA and biometric data to make an identification, law enforcement says.
We'll bring you live updates.
The FBI start by saying they are investigating this as an assassination attempt and the area is still an active crime scene.
Donald Trump has left the area his rally was held in Butler under the protection of the Secret Service, according to a statement by Pennsylvania Governor Josh Shapiro posted on X.
Shapiro said he was thankful that Trump was fine and wished him a full and speedy recovery. He added that he was "grateful for all law enforcement who responded, protected the former president, and worked to bring the situation under control".
He confirmed that federal law enforcement officials would continue to lead on the investigation into the shooting of Trump, while Pennsylvania State Police would lead the investigation into the shooting of the other victims.
"I respectfully ask that we treat our fellow Americans with respect and join together to universally condemn the unacceptable violence we witnessed earlier today in Butler," he added.