Cole Thomas Allen, the suspect in the White House Correspondents' Association dinner shooting, is being held in the Washington, D.C., Metropolitan Police Department's Third District after being released from an area hospital overnight, according to law enforcement sources.

Allen is expected to appear in court on Monday.

A Secret Service Uniformed Division officer was also treated and released overnight from a different area hospital, according to sources.

-ABC News' Jack Date

Britain’s King Charles and Queen Camilla reached out to President Donald Trump following the incident at the White House Correspondents’ Association Dinner, according to a royal source.

"Their Majesties have reached out privately to The President and First Lady to express their sympathies with all those affected on the night and their gratitude to the security services who prevented further injury," a royal source told ABC News.

The king and queen are scheduled to arrive on Monday in Washington, where they’ll be hosted by Trump and first lady Melania Trump for a state visit, according to the White House.

ABC News' Zoe Magee

International leaders expressed their shock and pledged their solidarity with the White House early on Sunday, after a suspect allegedly exchanged gunfire with authorities outside the White House Correspondents’ Association Dinner.

"I am shocked by the scenes at the White House Correspondents' Dinner in Washington overnight," British Prime Minister Keir Starmer said in a statement. "Any attack on democratic institutions or on the freedom of the press must be condemned in the strongest possible terms."

He added that it was a "huge relief" that both Trump and first lady Melania Trump, along with the other attendees, were safe after the event.

The suspect’s alleged actions were condemned by members of the governments of Kuwait, Pakistan, the United Arab Emirates and a host of other countries.

French President Emmanuel Macron decried the incident, saying, "The armed attack targeting the President of the United States last night is unacceptable. Violence has no place in a democracy. I extend my full support to Donald Trump."

"No political hatred can find space in our democracies," Italian Prime Minister Giorgia Meloni said. "We will not allow fanaticism to poison the places of free debate and information. The defense of the culture of confrontation must remain the insurmountable bulwark against every intolerant drift, to safeguard the values that found our Nations."

Israeli Prime Minister Benjamin Netanyahu said in a statement released by his office that he was "shocked" by the event, but glad the president and first lady "were safe and strong."

"We send our wishes for a full and speedy recovery to the wounded police officer and salute the US Secret Service for their swift and decisive action," Netanyahu said, according to his office.

Lebanon’s president, Joseph Aoun, sent Trump a cable after the incident, according to his office.

"And President Aoun expressed in his cable full solidarity with President Trump in the face of such regrettable events that target security and stability, affirming his strong condemnation of acts of violence in all their forms, and wishing that the United States of America enjoys security and safety," Aoun’s office said.

The chaos that erupted at the White House Correspondents' Association dinner after a suspect charged a security checkpoint brought back memories of the shooting at a Trump campaign rally in Butler, Pennsylvania, a White House deputy chief of staff said early on Sunday.

"Never thought I’d be hitting the ground again after Butler, Pennsylvania, as a result of shots being fired," Dan Scavino Jr., the deputy, said on social media. "Brings back a lot of terrible memories -- I am so thankful that everyone in attendance tonight is okay. We’re all in this together, stay strong!"

A gunman fired a barrage of shots at then-candidate Donald Trump in an apparent assassination attempt at a campaign rally in the Pennsylvania city in July 2024.