Security concerns are rising across the US political landscape after Charlie Kirk was fatally shot.

President Trump’s planned appearance was changed this morning “out of an abundance of caution,” officials said. His 9/11 speech, which was due to take place outside the Pentagon building, had been moved to its interior courtyard.

This afternoon, there was a bomb threat at Democratic National Committee headquarters in Washington DC. US Capitol Police later said it was not credible. "Out of an abundance of caution, Capitol Police is conducting an interior sweep of the building," a DNC spokesperson told CBS, the BBC's US partner.

Separately, Democratic Congresswoman Alexandria Ocasio-Cortez cancelled her event in North Carolina, citing security concerns and "out of respect for Kirk".

Conservative political commentator Ben Shapiro also withdrew from a previously scheduled event in Simi Valley.

And Republican Congresswoman Nancy Mace, who is running for governor in South Carolina, has told CBS that she will not hold any public events anytime soon due to security concerns, and that she plans to start carrying a firearm when possible.

Image source, EPA

Americast has recorded a special episode on Charlie Kirk's killing.

Justin Webb, Sarah Smith and Marianna Spring look at who Charlie Kirk really was, what made him so successful and how dangerous a moment this could be for America as a whole.

• Listen: A dangerous moment for America?

Earlier, we’ve been answering your questions about Charlie Kirk, after the Republican activist was fatally shot at Utah Valley University yesterday.

In case you missed it, here are the questions we covered:

Q: What was Kirk talking about when he was shot?

BBC Newsbeat’s politics reporter, Jordan Kenny, says eyewitnesses say Kirk was talking about gun control.

He’s been known to support carrying guns, previously saying it is “worth to have a cost of, unfortunately, some gun deaths every single year” to protect Second Amendment rights.

Q: Will his death affect gun law in America?

Jordan notes gun laws vary from state to state. Utah has “open carry” laws, meaning people can carry firearms in public. It’s a hot topic that will certainly be accelerated to the forefront of conversation after Kirk’s death.

It’s hard to say, but it’s unlikely this will lead to much change in the law, Jordan says.

Q: Was Trump’s video statement on Kirk’s death AI-generated?

Our disinformation correspondent, Marianna Spring, has noticed widespread speculation online about this.

There’s nothing to suggest the video was AI-generated, and it may just be the way it was edited.

She says it’s unlikely Trump would use artificial intelligence to comment on something so personal to him.

• BBC Verify has also looked at this with AI experts

Q: Why has there been wall-to-wall coverage of Kirk’s death?

Marianna points out that Kirk, through his use of social media, was able to reach a demographic Republican politicians typically struggled to capture. He drew attention as someone willing to go beyond the echo chamber and debate people who disagreed with him.

Despite not being a politician, he was instrumental to Trump’s second presidential win.

Q: Why would Trump put the US flag down to half-mast for someone who isn’t a politician?

Washington-based reporter Caitríona Perry points out that Trump can do this for whomever he pleases. Kirk was a good friend of the president and his son. The half-mast is a mark of personal respect.

Q: How concerned should we be by responses from both sides?

Kirk's death has ignited a whole debate, as indeed his life did, says Caitríona.

The Republicans and Democrats have been pointing fingers at one another, each blaming the other’s rhetoric for the fatal shooting of Kirk. It’s not clear, though, what the reason behind the shooting was.

Earlier, we told you that the FBI said it found a high-powered bolt-action rifle in a wooded area where authorities believe the gunman fled.

We can now bring you more information about this.

Officials have confirmed to CBS, the BBC’s US partner, that the weapon was an imported Mauser .30-06 bolt-action rifle.

As mentioned, investigators also found a "footwear impression", a palm print and forearm imprints at the scene.

Bernd Debusmann Jr
Reporting from the White House

I’ve just got off the phone with Lawrence Muir, a former official in Trump’s first administration who was involved in hiring staff during the 2016 transition ahead of the first term.

Muir tells me Charlie Kirk’s influence was felt even then, when he was much younger and Trump’s political career in Washington was still in its early days.

“It was the main recruitment vehicle for younger people,” he says.

Kirk, Muir adds, allowed the Trump administration to address what he called an “enthusiasm gap” among young conservative voters.

“He gave young conservatives a chance to feel like they weren’t alone,” he says.

But Muir says Kirk’s more far-reaching impact was in reaching other conservatives, or would-be conservatives, with an understanding of social media and how to connect with young people.

“Some people weren’t looking to have careers in government, but more to have a public influence,” he says.

“What [Kirk] really did was give a launching pad to those who weren’t as interested in becoming bureaucratic functionalities, but were in going out and building winning coalitions.”

Image source, Getty Images

Image source, Reuters

Charlie Kirk's body will be flown on Air Force Two - the vice-president's aircraft - to Arizona, the state where he lived, according to officials who have spoken to the BBC's US partner CBS News.

Vice-President JD Vance flew to Salt Lake City on Thursday to retrieve Kirk's casket and will transport it to Phoenix, where his family lives, on the vice-presidential aircraft, the officials said.

Vance and Second Lady Usha Vance will travel with Kirk's family and some of his friends to Arizona.

Kirk's body was transferred from the hospital to the medical examiner's office on Wednesday night, authorities said earlier.

Kirk shooting leads to misinformation onlinepublished at 18:30 BST 11 September

18:30 BST 11 September

By Olga Robinson and Kayleen Devlin

As we write this, there’s still no confirmation about the identity or motivation of the person who shot the right-wing US influencer Charlie Kirk in Utah yesterday.

But that hasn’t stopped people on social media from attempting to identify a possible suspect immediately after the shooting, which has led to multiple cases of misidentification.

Online users first seized on a video of a man being apprehended by police on site. It was later confirmed he was not involved - but footage of him being described as a suspect is still circulating.

There were also attempts to pass off old footage as related to the killing, like that of US comedian Sam Hyde, whose images holding a gun regularly get shared in the aftermath of violent incidents.

Misidentification is very common in the aftermath of shootings as people try to get quick answers in a rapidly developing situation when there’s little clarity initially.

So it’s very important to be extra cautious when sharing any information naming individuals in the immediate aftermath.

• Meanwhile, we've also looked at the online debate about whether Trump's video on Kirk's killing is AI-generated

Image source, TRUTH SOCIAL

Searching for clues in FBI images of 'person of interest'published at 18:25 BST 11 September

18:25 BST 11 September

By Shayan Sardarizadeh, BBC Verify

BBC Verify is trying to examine the two images released by the FBI showing a “person of interest” in the shooting of Charlie Kirk.

We ran the two images through a face search engine to see if it could find similar faces among the millions of images and videos that are publicly available online.

But owing to the low resolution of the images and the fact that the person seen in them is wearing dark glasses, a face search was not successful in finding a match.

It’s worth remembering that the authorities said last night that they were working with “information from CCTV” at Utah Valley University but “you can guess what the quality of that is”.

We also did a reverse image search on the black top with a design in the middle and were able to find similar images online.

We think it may be an image of an eagle flying, with a background of the American flag, which is a popular design in the US.

Based on the low resolution of the photos, it's not possible to work out whether there are any words written on the design.

Image source, FBI

Christal Hayes
Reporting from Orem, Utah

Image source, Christal Hayes

I’ve just spoken with McKinley and Anthony Shinkle - two cousins who are also first-year students at Utah Valley University - outside their flat.

They made signs reading “freedom” - the word on Kirk’s shirt when he was killed - and “you can’t kill the truth”, and put them in their window in the popular student housing complex just outside campus.

“We had to do something and this felt like a moment where we needed to say something,” McKinley, 25, tells me as other students walk by.

The Navy veteran says he and Anthony were heading over to see Kirk speak when the shooting started.

He says the killing will only elevate Kirk’s message.

“He might be gone, but what he did and what he said is never going to die.”

It’s felt ominous knowing the person responsible hasn’t been caught.

“We didn’t sleep here last night,” Anthony tells me, saying family nearby took them in. They likely won’t stay tonight if the killer is still at large.

Down the street, another vigil has appeared for Kirk with candles - some still lit - and flowers.

A sign reading “Thank you Charlie” is propped up against an American flag.

Image source, Christal Hayes

An influencer who once publicly debated Charlie Kirk says he is "distraught" to hear of Kirk's death.

Dean Withers, 21, was one of the many "liberal college students" who took on Kirk last year in a video which has nearly 32 million views on YouTube.

Kirk defended the statement "abortion is murder and should be illegal", while Withers argued against it.

Reacting to the 31-year-old's shooting, Withers says he is "sad, distraught", adding he cried when he learned the news.

"It should come as no shock to yourself when I tell you that I think Charlie Kirk was a bad person. I’ve made that very clear over the last year," Withers says. "But does that mean I think he deserves to lose his life? No."

In the video, Withers condemns gun violence as "always disgusting, always vile and always abhorrent".

"My thoughts and prayers go out to Charlie Kirk’s friends, family, children, loved ones, as well as every single person in attendance at his event today in Utah," he adds.

Gabriela Pomeroy
Live reporter

I've been speaking to students across the political spectrum about their reaction to the news of Charlie Kirk's death.

Adam Saar, a 21-year-old student in Cleveland, Ohio, says “I disagree with Charlie Kirk on every policy position. But I think the model of seeking out civil discourse through conversation is the right way to go about politics.

“On campus today, I have many conversations with people, and everyone agrees it is rather shocking."

Saar says he has seen comments on social media "not necessarily celebrating, but rejecting the idea that anyone should be mournful or sad about it.

"Most people I know don't agree with him politically but we are very disturbed by what happened.”

Saar says he is on the "left of the political spectrum" and he disagrees with Kirk on gun rights, immigration and LGBT and trans rights.

“I have seen comments made online by people who say it's karma given his views on gun rights – but I would not go around saying that. No such idea or belief should condemn someone to face violence or death."

The FBI has just announced that it is offering a reward of up to $100,000 (£73,645) for information.

It says the reward will be for "information leading to the identification and arrest of the individual(s) responsible for the murder of Charlie Kirk".

People with information are asked to get in touch, external via a phone number and can submit photos and videos online.

Earlier authorities said they had received 130 tips from the public as of this morning.

Image source, EPA

We're continuing to monitor reaction to the killing of Trump ally, Charlie Kirk.

US Director of National Intelligence Tulsi Gabbard says Kirk is a "one of a kind" and a "courageous soul" who "truly loved our country".

"I'm devastated that Erika lost her husband today, their children lost their father, and so many of us lost a dear friend," she writes.

Gabbard, like others who have speculated about the motive behind the fatal shooting, suspects that Kirk's shooter "sought to silence him, using violence to take away his freedom of speech by ending his life".

She writes that he "stood up to such fanatics who hate freedom".

As a reminder, there has been no confirmation from officials on the identity of the suspect, nor the motive behind the shooting.

The latest drone images from the site of the shooting, at Utah Valley University in Orem, show the area is still sealed off by authorities.

Litter has been scattered across the grassy seating areas, presumably left behind by people as they fled in panic. Our reporter is at the site and described the scene as "frozen in time".

Image source, Reuters

Image source, Reuters

Image source, Reuters

Image source, Reuters

As the FBI releases images of a "person of interest" in the killing of Charlie Kirk, let's bring you some of the details authorities shared in an news conference earlier today.

Officials said they were “confident in our abilities" to track the shooter and they had "good video footage" of the suspect.

As well as locating a high-powered rifle, officials said they had also found a "footwear impression, a palm print and forearm imprints" which are being analysed. They also said they had tracked the shooter's movements directly before and after the shooting.

Earlier, investigators said they were "working through some technologies and some ways to identify this individual" and, if they are unsuccessful, they will then share images publicly with the media to help identify them.

The officials said they had already visited the neighbourhoods where the shooter is believed to have fled through, contacting witnesses and people with doorbell cameras.

For those just joining the page, the FBI have released the first pictures of a "person of interest" in the shooting of Charlie Kirk yesterday. Let's take a look at the latest developments.

What we know:

• In the last few minutes, the FBI in Salt Lake City released images of a "person of interest" in the shooting, they are asking for the public's help in identifying them
• These are the first images law enforcement has shared of an individual they believe may be involved in Kirk's death
• The killer is still at large, two people questioned earlier by police were released
• In a news conference, authorities said the shooter appeared to be on the roof, before fleeing the scene at Utah Valley University
• Authorities have also located what they believe to be the weapon used in the shooting and said the suspect "appears to be of college age" - here's a full recap

What we don't know:

• The identity of the suspect remains unknown
• The motive - speculation on social media is rife, but nothing has been confirmed by authorities

We're still monitoring developments from officials in tracking down Kirk's killer - stay with us right here as we bring you the latest.

The FBI in Salt Lake City has just released pictures of a "person of interest" in the shooting of Charlie Kirk yesterday.

They are asking for the public's help in identifying the person. They are the first images law enforcement has released of an individual they believe may be involved in Kirk's death.

You can see the photos below:

Image source, FBI

Image source, FBI

Image source, Getty Images

The US Undersecretary of State, Christopher Landau, says "appropriate action" will be taken against "foreigners who glorify violence".

In a post on X, Landau says he has been "disgusted" to see comments on social media "praising, rationalising or making light" of the killing of Charlie Kirk and those who "glorify violence and hatred" are "not welcome visitors" to the country.

He says he has directed consular officials to "undertake appropriate action" and tells his followers "to bring such comments by foreigners to my attention so that the State Department can protect the American people".

In a response to a tweet, Landau then says he will direct consular officials to monitor the comments to his post.

BBC Visual Journalism Team

While a manhunt is still ongoing to find the killer of Charlie Kirk, investigators have shared some details about the suspect.

In a news conference earlier today, officials said the suspect "appears to be of college age" who arrived on campus at 11:52 local time yesterday.

After the shooting, he is believed to have jumped off the roof of a building on campus, fleeing "into a neighbourhood," officials said.

Video footage taken from inside a building behind the gazebo that Kirk was in appears to show someone running across the roof of the Losee Center building, right after the shooting.

We have analysed that footage below.

Gabriela Pomeroy
Live reporter

Image source, Chandler Crump

I've been speaking to a young activist, Chandler Crump, who says meeting Charlie Kirk at the age of 14 "changed my life".

Chandler - who is now 20 and describes himself as a Gen Z political commentator - first met Kirk at the Young Black Leadership Summit in 2018, which was sponsored by the conservative group Turning Point USA - founded by Kirk.

Since then he has been to every single Turning Point national conference and met Kirk many times.

“We were young black leaders wearing Maga hats and he said it doesn’t matter if you are black or white,” Chandler says. “Political figures tend to speak down to us - but he did not. He is paying attention to us. That’s why young people listen to him.”

Growing up in Atlanta, Georgia, Chandler says: “I met Charlie at a time when there was a sense that young people were down and out and struggling. We felt weak and he empowered us."

Chandler says he is “absolutely convinced” that Kirk helped President Trump win the 2024 election. “The movement worked hand in hand with the Trump campaign get out the vote for Trump," he says.

Speaking on the phone through tears, Chandler feels a real sense of loss. "I am torn up. It hurts so much.”