New York Times photographer Doug Mills captured an iconic image of the projectile passing by Donald Trump's head.

A New York Times photographer captured a stunning image of a bullet flying by Donald Trump's head during his Pennsylvania campaign rally.

I was part of that small pool that sits right up in the buffer zone which is just feet, sometimes just inches, from the podium," Mills described.

"(In) the moments right before the the bullets rang out I was literally looking up at this huge flag that was up above him. While he was speaking. I thought, 'Okay, I'm gonna try and get some pictures of that flag flying,' and then he gestured to his right...and all of a sudden the shots rang out," he said.

"I looked up, I kept taking pictures at the same time, and then when I saw him fall behind the podium, I thought, 'Oh, dear God, he's been shot.'"

King Charles wrote a private letter to former President Donald Trump on Sunday, Buckingham Palace said in a statement.

The correspondence was delivered via the U.K. Embassy in Washington, D.C., the palace said on Monday.

"We do not divulge contents of such private correspondence, but safe to surmise that the sentiments are in keeping with those communicated by the PM," the palace said, a reference to Prime Minister Keir Starmer.

The prime minister said Sunday he was "appalled" by the assassination attempt.

Former President Donald Trump praised Secret Service agents who acted quickly to protect him and get him offstage following the attempt on his life at his Saturday rally in Pennsylvania.

"They did a fantastic job," he said in an interview with the New York Post on Sunday.

Reflecting on the shooting, Trump said, "I'm not supposed to be here, I'm supposed to be dead."

Trump praised the crowd at his rally for how they reacted in the moment.

"A lot of places, especially soccer games, you hear a single shot, everybody runs. Here there were many shots and they stayed," he said, adding, "I love them. They are such great people."

In the interview, which the Post reported also included a reporter from the Washington Examiner, Trump addressed the call he received from President Joe Biden saying it was "very nice."

Sen. Lindsey Graham, who the Post reported was on the flight with Trump, said of the former president, "He feels like he has a new lease on life."

The FBI says its investigation into the assassination attempt on former Donald Trump remains very active.

An official who spoke to ABC News late Sunday night said that while the evidence currently points toward a lone wolf shooter, the FBI will not be comfortable until they fully exploit the suspect's phone and dig deeper into his life.

In a statement Sunday night, the FBI said in a statement it "continues to conduct logical investigative activity to determine if there were any co-conspirators associated with this attack."

Additionally, the FBI said a motive for the shooting still has not been identified.