The FBI said late Saturday that it believes an identification has been made on the suspected shooter, but are not yet released a name "as it is a very sensitive point in the investigation."

"Early indication is that this is a lone wolf," the FBI said in a statement. "But the situation is fluid and the investigators want to be absolutely certain that this person had no support and that no one knew what was coming."

The gunman opened fire with a rifle from the roof of a building about 200 to 300 yards away from the stage where Trump was speaking. A U.S. Secret Service counter-sniper team immediately killed the individual.

Trump left the Butler, Pennsylvania, area just after 11 p.m., according to Gov. Josh Shapiro.

"Under the protection of US Secret Service and with the assistance of the Pennsylvania State Police, former President Trump has now left the Butler area," Shapiro said. "Lori and I are thankful that his team reports that he is fine and we continue to wish him a full and speedy recovery."

The former president left the area about five hours after the shooting took place.

Trump's plane took off from Pittsburgh, but a destination was not released.

An investigation is underway after a shooter appears to have opened fire on former President Donald Trump at a rally on Saturday. Trump is "fine," but at least one spectator was killed. The shooter was also killed.

Here's what we know about the apparent assassination attempt.

President Biden spoke with Trump, a White House official told ABC News.

Biden also spoke with Pennsylvania Gov. Josh Shapiro and Butler Mayor Bob Dandoy, the official said.